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Saturday, June 15, 2019

Hydraulic Oil Coolers Eight Reasons Why Hot Hydraulic Oil will Cost you Money, 2.4 will surprise you.

1. Hydraulic Oils or Transmission Oils operating at temperatures above 65°C (150°F) will start to deteriorate at an accelerated rate, this will result in shorter oil change periods. For Example having to change your Hydraulic System's oil every 1000 hours instead of 1500 hours or your transmission oil every 15,000 KM instead of 30,000 KM. 

2. Hot Oil damages Gaskets and Seals and this may result in Internal as well as External Leaks. 

2.1 Internal leaks reduce efficiencies, power and or torque of hydraulic cylinders, pumps and motors and in the case of a transmissions may cause erratic performance, slow acceleration and or gear shifting.

2.2. External leaks can make a mess of your mobile equipment as leaks are blown all over the underside of your vehicle, dust and grime will then stick to the oily components creating an ugly sticky mess requiring cleaning.

2.3 Oil leaking or dripping onto a non absorbent floor not only makes a mess but also creates a potentially dangerous slip hazard.

2.4 Oil Leaks onto the ground could be interpreted as contamination and pollution and you risk being fined. The actual or perceived risk of environmental impact from an oil leak is real, so stop that leak or at the least clean it up and save yourself the potential of a fine and legal action!  

A recent Client of ours was sent a clean up bill for AU$3,500 when their excavator was left unattended and unchecked over the weekend leaking hydraulic oil into the ground on a particularly sensitive government construction site.
2.5 Large external leaks if left unchecked will reduce or deplete the oil level of the hydraulic circuit causing even more heat to be generated, poor performance, and eventually catastrophic damage. 

3. Lastly the Hydraulic system's efficiency is reduced because the oil viscosity changes and more power losses are experienced resulting with even more heat being generated with reduced machine performance and or productivity.

ASA Hydraulik LL 06 Oil Cooler with 12 Volt  DC Fan
Capable of Cooling an Oil flow of up to 50 Lt/Min 

How to Calculate the Size of an Oil / Air Cooler.

When there is resistance to oil flow, pressure as well as heat are generated, the temperature of a hydraulic oil in a circuit will continue to increase until the added thermal energy has the same value as the combined radiation and convection energy absorbed by the surrounding atmosphere.

After a certain operating time the oil temperature rise will eventually slow and then stabilize. 
If this stabilized oil temperature is too high, the oil must be cooled because as mentioned above Hot Oil Costs Money! 

In order to choose the required cooler type we must know the required cooling performance. 

How to find out the required cooling performance with the rise in Oil Temperature for an High Performance Engine or Existing Hydraulic Circuit.

For existing Hydraulic circuits the heat input to the oil can be accurately determined if the rise in the Oil's temperature is measured over a certain period of time. This then gives the amount of heat to be exchanged by the cooler in order to maintain the system at an optimum operating temperature.

 PK = m x c x (t2 – t1) / 1000 T

PK = required cooling performance [kW] 
m   = Weight or mass of the oil in reservoir [kg] (see below for how to calculate this)
c    = speciic heat capacity [Wh/kg°C]
         (c~0,53 for hydraulic oil, c~1,16 for water) 
t1   = oil temperature at the begin [°C] 
t2   = oil temperature at the end [°C] 
T    = heat up time [hours] 

To quickly Calculate the weight in KG of hydraulic oil in a tank use the following formula.
Length x Width x Height of tank in cm then multiply by 0.00088 
eg a hydraulic tank of 80 cm long  x 40 cm wide x 60 cm high cm 
80 x 40 x 60 =192000 cm³ 
192000 x 0.00088 = 168.96 KG 

for cylindrical tanks 
measure the diameter D and length or height H in cm and then use the following Formula
V= πD²H/4
If you are not confident in doing the math yourself, Try this Secure Online Application by ASA Hydraulik to assist you in calculating the right size and model of oil cooler. 

Dimentions of ASA Hydraulik LL 06 Oil Cooler.  

Another Approximate calculation The required cooling performance PK can generally be calculated as in the following formula

PM = p x Q oil / 600 x η 
and then use 

PK = PM (1 – η)

where as 
η = general Pump Efficiency (70% efficiency use the value of 0.7) 
PK = required cooling performance [kW] 
PM = required motor power [kW] 
p = oil pressure [bar] 
QP = oil flow [l/min]

As a guide hydraulic circuits with constant flow pumps have a general efficiency from approximately 70-75%,
therefore use a η of = 0.7 to 0.75
Circuits with variable Flow pumps have a general efficiency from approximately 75 to 80% therefore use an : η = 0.75 to 0.80. 

Selection of the cooler:
After you have calculated the required cooling performance (PK ) using one of the above formulas, the specific cooling performance (Pspec) must now be determined. 

Pspec = PK / toil – tL (kW/°C) 

Pspec = specific cooling performance (kW/°C) 
Toil     = oil temperature inlet (°C) 
TL      = air temperature inlet (°C)

Once you have these values you can then compare various charts listed below to get the required size of cooler. 

Performance Characteristics of ASA Hydraulik LL 06
12 Volt DC Fan Ventilated Oil Cooler. 

Sunday, March 24, 2019

Flow dividers & Phasing cylinders get two or more Hydraulic Cylinders to Extend Retract at the Same Time.

In Hydraulics they say that getting two or more cylinders to move at the same time and at the same speed is one of the hardest things to do.

We had a call from a customer who recently purchased a full hydraulic kit including a 12 Volt DC hydraulic power pack with push button pendant control as well as hydraulic cylinders or rams, do it yourself D.I.Y High Pressure Hydraulic Hoses and Hose Fittings,  he was in the final stages of completing his Hydraulic Motor Home Canopy. He installed and set up two Hydraulic cylinders to open up a hinged frame for a canvas canopy on the motor home but he could not get the canopy to move smoothly or evenly as the cylinders would not extended at the same time or speed.

D.I.Y Hydraulic Power Kits for any Project please click here

The cylinders were exactly the same size, same bore, same stroke, same rod diameter and had a single in and out supply split with Tee fittings to supply both cylinders.

Australian Made Hydraulic Cylinders
from  1.5" to 5" bore with up to 48" stroke. 

To view our range Hydraulic Cylinders and Rams please click here 

Fact No 1 Hydraulic oil under pressure will always take the path of least resistance.

If one of the cylinders has more load or one had tighter seals or one had a meter more hose or even one more hydraulic fitting the cylinder circuit with least resistance, least friction or least load or work to do will always move first.

Even if the the 2 cylinders are physically connected to a strong a rigid frame like those on a skip bin track or compactor one cylinder will always move before the other eventually causing jams or at the least creating twisting forces.

As most of the work and Plumbing on the hydraulic motor home canopy had been completed we recommended a Cartridge type Hydraulic Flow Divider / Combiner, these items have errors of between 5% and 15%  at dividing and combining hydraulic oil flows. These errors were considered acceptable by the client.

A Cartridge Flow Divider will divide a single hydraulic flow
into 2 almost identical flows. It will also works in reverse to combine
 2 divided flows into one combined flow.    

Need a Hydraulic Flow Divider please click here

If more accuracy is required to move hydraulic cylinders in unison then we would recommend a Gear Flow Divider, this type of flow divider uses two or more accurately machined gears to mechanically split or combine flow, an error of 5% or less is achievable all be it at a little more cost compared to a cartridge style flow divider.

2 way gear flow divider with built in
differential pressure relief valves 

Need an accurate Gear Flow Divider please click here

The Most accurate way to move two or more cylinders at the same time is with specially manufactured Phasing Cylinders.
Last Christmas the Owner of a 12 metre Mustang Cruiser pleasure boat complained to us that the hydraulic cylinders lifting the floor over his boat's engine room were not lifting evenly, after investigation we discovered that the installation had Phasing Cylinders.

Phasing Cylinders by design are manufactured to move at the same time and speed, BUT ONLY if they have been correctly set up and installed and only if the hydraulic seals are in perfect condition

This synchronized movement is accomplished in the following way.
As a Double acting cylinder is extended the oil on the rod side of the cylinder is displaced, if you take the displaced oil and send into another smaller bore cylinder with the same stroke designed to take all the oil displaced from the first cylinder you will get them to move at the same time and speed.

Contact Us for Technical Support & Hydraulic Repairs please click Here

Take 2 minutes to look at our You Tube Video showing what we found on strip down and how we bench tested and finally got the engine room cover to move up and down smoothly.
Remember the boat's engine room cover has two phasing cylinders.

Check out this informative video from Bailey International for a visual Demonstration

We Raise the floor by extending both cylinders but by sending pressurized hydraulic oil only into the bottom of the first Larger Cylinder.
We lower the floor by retracting Both cylinders by sending oil only into the top of the second Smaller Cylinder. Our 2 min video.

Cheers Everyone
From the team at Mobile Hose Fixers & Hydraulics
Hydraulic Hose Repairs and a whole lot more.

Thursday, March 21, 2019

How to Dismantle & Reseal a Hydraulic Ram or Cylinder,.20 Steps to Avoid Mistakes.

How To Dismantle, & Reseal a Hydraulic 
Cylinder 20 Steps to avoid mistakes.

1. Clean the cylinder in wash bay to remove oil, grease and dirt. 

Before commencing disassembly have your mobile phone or digital camera ready and take a picture each step as a part or component is removed. 

2. Set up cylinder to be clamped in the floor vice, with the exception of small convertible type cylinders DO NOT clamp cylinders on a bench mounted vise. Try and clamp the cylinder on the flat part of the clevis, if this is not possible use an appropriate sized rod or pin and clamp the pin in the vise and place end of barrel onto the pin.

3. Finally Level up and support gland nut / rod end of the cylinder on sturdy blocks of wood.

4. Whenever possible try and remove excess oil from both sides of barrel by extending and retracting the rod, collect all waste oil in suitable containers and empty into waste oil drum for future collection by approved registered waste collection company.

5.  Place oil container underneath gland nut to collect oil from cylinder when dismantled.
Important this is one of the most important and potentially time consuming steps so preparation, selection of the most appropriate tools and attention to detail is paramount. 

6. Identify style of gland nut and use appropriate tool to remove gland nut from cylinder.
Check for locking tabs or grub screws on gland nut, e.g.  Yanmar has locking tabs  , JCB cylinders have grub screws. 

7. Most cylinder gland nuts are threaded into the barrel and need to be unscrewed counter clock wise (caution) threaded gland nuts can be extremely tight so some care as well as perseverance is required. 

Typical Screw in Gland Nut

Removed Screw in Gland Nut. This Gland Nut is Damaged. 

8. At this stage take a couple of Minutes to Check for Grease nipples lubricating the rod and barrel clevis pins. Always remove and clean out grease points to ensure that grease can get to the pins as sometimes hardened bushes rotate in a dry swivel connection and the grease way  gets blocked,  Always replace grease nipples with new ones.

9. Remove rod assembly from barrel and collect any oil that comes out in oil tray.

10. Remove barrel from vice and set up rod in vice.
Before attempting removal of piston take a picture with your phone or tablet so you can check which orientation to put it back together.

11. Check for grub screws or scotch keys in piston or nut retaining piston, screws may be under seals.  Identify style of piston or piston nut and use appropriate tool to remove piston from rod.
 Take picture of seals position and location on gland and piston so you know which way to put them back in.

12. Once gland nut and piston is removed from rod start to remove seals from both gland nut and piston carefully as you will need samples to measure up and order.(DO NOT BREAK ANY)
 Keep all old seals in a plastic bag to show customer what has been removed and replaced.
 Don’t assume just because 2 cylinders look identical that they have the same seals. (Speaking from experience)

13. Once all seals wear bands and or bushes are removed use telescopic gauges (internal caliper ) to check bore of barrel in several locations. (check three places at bottom of barrel, three places in middle and three places at end of barrel.)

14. Also measure rod and put a straight edge on a rod to check for any damage. (Damage consists of rust marks, dents, scratches, plating removed.)
 If either part has imperfections (scratches/ dings) then repair or replace. If not possible then order new cylinder.

15. SEAL, WEAR BAND AND GLACIER BUSH MEASURING (if the clearance is more than 0.04mm between glacier bush and rod, will have to machine or press out the glacier bush)
After seal removal, search ‘grid for seals” in MHF folder, if cant be found look on Job card wall.

16. Measure seal and wear band grooves metal to metal only. Draw & label sizes on grid paper. Put your name, date & job on grid paper
Scan & email with order number. Don’t fax.

17. Measure up seals and seal grooves then order a new set from either manufacturer of cylinder or from reputable seal supplier. (Ensure parts removed are correct for the job). Compare dimensions with part numbers and with sizing of components.

18. Check all components for dimensions before re assembly.
 Put gland nut and piston in lathe and use emery paper to clean all rust and marks from both (Make sure to clean all surfaces, especially where seals sit).

19. If applicable put parts in wire wheel to remove any imperfections.
 Once all clean re install seals in both gland nut and piston.
 If using one piece Teflon seals hold seals tight to piston with piston ring compressor or a hose clamp and piston assembly in a plastic bag and then into freezer for 20 mins this will shrink Teflon seals and make them easier to install.
 Oil up and install gland nut on rod, lock tight piston on if held on by nut.(Remember to put piston in the correct orientation, to prevent damaging piston seals. CHECK PICTURES YOU HAVE TAKEN WHEN  PULLED APART)

20. Oil up barrel and install rod assembly into barrel and tighten gland nut.
 Put cylinder on test bench and pressure test in both directions, retract rod all the way in and plug the piston side of the cylinder. Pump oil into the rod side and check for bypass.
If all ok then clean up, put Mobile Hose Fixers sticker on the cylinder and bill customer for professional job.(Remember to also bill clean up time after job is finished)

We have been offering a hydraulic cylinder reseal and rebuild services for about 9 years now and we thought we would write about a couple of particularly interesting jobs we started to work on in our new larger heavy equipment Hydraulics Workshop in Nerang,  Gold Coast Australia last week. 

Our Nerang Workshop Manager Denis with Our Biggest 

Hydraulic Cylinder Reseal To Date 

a 3,000 mm Stroke 250 mm Bore Monster weighing in at 2300 kg.   

Also this week one of our clients who business has grown incredibly rapidly, recently purchased mobile compactor for his document destruction business. We gave its hydraulics systems and hardware a health check and prescribed overhauled Hydraulic Pumps and we also rebuilt some of the numerous compactor hydraulic cylinders with new rods and seals.

Hydraulic Cylinders or Hydraulic Rams are found on great majority of equipment.

On earth moving equipment they are designed to be STRONG and to work in the worst conditions imaginable, that is, in dirt, rocks, dust and mud and at pressures up to 270 BAR (4000 PSI).  So most cylinders will only come apart if you are equipped with all the special and necessary tools required to literally force these components apart.

Typical  Cross Section of Hydraulic Ram or Cylinder.  

This particular cylinder below is off a 7 ton Kobelco excavator, it has completed about 4000 hours of work, it has a 100 mm Bore, 850 mm Stroke and 55mm Rod diameter.

Generally there are 2 parts where a large Force is required to dismantle a Hydraulic cylinder.

1. Unscrewing the Gland nut on the end of the cylinder. These usually come apart .... eventually with the use of a correctly sized "C" spanner (or Pinned Cam tool) and a long bar for leverage.
The exception are some Yanmar Cylinders that are made to such close tolerances that the threads usually seize or bind up after a turn or two, .... then... liberal amounts of heat (enough heat to usually melt the seals!) and lots force are required to unscrew them.

Gland Nuts usually screw onto the end of a cylinder's Barrel
and are then done up very tightly.

 2. Unscrewing the nut that holds the Piston onto the Piston Rod.
These nuts are usually done up extremely tight as the piston is the component that has very large forces acting on it in alternating directions of each in/out cycle of the cylinder.

Piston Nut Assembly these Strong Steel Pistons usually screw on to the end
of the Cylinder''s Hardened Chromed Rod .

On the Kobelco cylinder despite all our efforts (including heat) we could not undo the nut. The 300 KG steel bench was flexing and creaking under the strain! We could apply more force but we knew the bench could not handle it and would flip or tip over under the high torque we would need to apply.
Bolting the bench to the floor was not an option as its construction was designed for high weight and it was on wheels so large twisting forces were not an option.

Time was now a critical factor as the customer was picking up the cylinder the next day, So we quickly bolted a 2 meter long steel beam to the concrete floor and then bolted a 200 mm steel vise to it.

We still use this floor beam and 200mm vise to dismantle some of the 

smaller cylinders that come through our doors with great success. 

We then tried again and our floor mounted beam and vice worked a treat!
By our calculations we applied around 4500 NM (3300 foot pounds) of torque to the nut before it came loose.  To put it into comparison the typical torque spec to properly seat a crankshaft balancer on the Chev LS1 V8 engine is 330 NM (240 foot pounds) of torque.

Denis Checking out next acquisition a
massive Hydraulic Cylinder Breakout Bench 

Cheers and all the best for 2019 !
From the team at Mobile Hose Fixers & Hydraulics,
"Living and Working the Dream" on the sunny Gold Coast, Australia.

Friday, March 15, 2019

How to repair a Hydraulic Hose the Complete Guide that will Save you Time and Money


Removing Repairing and or replacing a damaged Hydraulic Hose is not generally very difficult. That being said there are quite a few important steps to ensure the final outcome is a success.

With a little bit of planing, preparation and using the comprehensive guidelines below you and your machine's hydraulic system will be back up and operating in the shortest possible time and or with the least effect to your wallet or bank balance.

For 13 lucky years my team and I have removed manufactured and installed over 50,000 hose assemblies.

If you are looking to join the hydraulic hose replacement industry and earn some good Money in the process this blog is a good first introduction on the basics of what we do, why we do it and how we do it.

It has been put together by the team at Mobile Hose Fixers & Hydraulics as both a guide and a reference to assist you to carry out your hydraulic hose repair work safely and efficiently.

Before you start you must make a through review of the surroundings and situation, identify the hose AS WELL as any other spare or replacement parts necessary to fulfill the requirements of the application.

It is imperative that you observe and obey all safety requirements before, during and after work has been carried out. 

You are required under the Workplace Health and Safety Act to notify the owner or operator of any unsafe conditions or possible premature failure of hoses or associated fittings.

Care must be taken to avoid oil spills. Appropriate caps and plugs must be fitted and drip trays used in order to minimise spills. When spills occur, it is necessary to use rags or oil absorbing materials such as pads and granules to ensure that the oil is removed.

Note: In Australia and most other parts of the world It is an offence against environmental legislation to allow oil to be introduced into the storm water drainage system. Under no circumstances may spilled oil be flushed or dumped into gutters or storm water drains. Take all spilled and waste oil away with you for proper disposal or collection by a registered waste organisation.

Although this is a comprehensive blog that outlines most procedures and gives practical advice on hose making. You may still,  however, come across unusual situations requiring creative solutions.

Use your initiative to resolve these situations, Above all you must always follow  safety procedures, and ensure that all checks are carried out under normal working conditions.

  1. Safety First ALWAYS ( P.P.E)
  2. Pressure Force and Gravity
  3. Prepare to get Dirty (oily hands or neoprene gloves)
  4. Finding the Damaged Hose (trace the leak to the source 😉)
  5. Understand the Mechanics (what does the hose do?)
  6. Make the machine safe 
  7. Protection from the Elements sun wind rain
  8. Tools more Tools Special Tools and Techniques
  9. Get to it.  Perseverance and Resilience.
  10. It's OK to Swear (it helps release stress and tension) 
  11. Colored cable ties Plugs and Caps (keeping it all Organised and Clean)
  12. Secret tricks to help remove the old hose and replace the new hose (rope and wire and tape are your friend)
  13. Once the Hose is out (now what are your Options?) 
  14. Store Bought OEM, After Market, or D.I.Y.
  15. Store
  16. D.I.Y
  17. STAMPED and APPS to help you identify what you require.
  18. Reusable fittings advantages and Disadvantages.
  19. D.I.Y Video, Hydraulic Hose Assembly with Reusable fittings.
  20. Hose types and Basic Identification 

All our new team members get quickly introduced, trained and then relentlessly questioned and tested on the acronym S.T.A.M.P.E.D. why, because we feel we have proved it thousands of times over that questions asked and answers received based on these 7 letters result in a more effective, durable and safer hydraulic hose repair.
We have completed over 50,000 High Pressure Hydraulic Hose Repairs, and we have found that  starting your questions based on this 7 letter acronym will help even the most inexperienced team member pinpoint with much better accuracy just what hose type and construction will be most suited for the application.

From Top Left Fabric Braid up to 500 PSI  (35 Bar)

Single Wire Braid up to 2000 PSI (135 Bar)

Multiple Wire Braid up to 4000 PSI (270 Bar)

Multiple Spiral Wire Wrap up to 6000 PSI (410 Bar) 

Read on to find out how you can get your self out of trouble and back working with the right hose most ideally suited for you and your machine's requirements.

So when you contact us expect to be asked a few important questions using the Acronym  S.T.A.M.P.E.D and then, based on your answers, we will formulate the best, quickest and most economical solution for you. 
Our solutions or options may include.
  • Sending one of our Mobile Service Technicians out to do the job for you.
  •  Arrange for you bring the hose or even the entire machine to our Gold Coast service center.
  • Us packing and sending you the parts or the completed hose assembly you need along with instructions to Do It Yourself (DIY).
S.T.A.M.P.E.D stands for 
  • S = Size 
  • T = Temperature
  • A = Application
  • M = Media
  • P = Pressure
  • E = Ends
  • D = Delivery 

S = Size
The size or more importantly the Hose Inside Diameter. 
Generally you will need to replace the original hose with one of the same inside diameter. On long runs of pressure wash hose for example we may recommend the next larger size available to maintain original design flow and pressure drop. 

Three (3 ) Hose Samples each with a different inside diameter
From top to bottom 1/4" (6.5 mm) 1/2" 12.7 mm and 1" (25.4 mm) 

 T = Temperature,
For most Australian operating conditions it is sun and heat rather than cold that causes damage and deterioration in hydraulic hoses. 
The operating temperature is important in selecting suitable materials of Construction. Normal hydraulic hose will typically run around 60 to 75 degrees Celsius, transmission and power steering hoses may operate up to and around 120 degrees Celsius
Truck air brake compressor hoses may reach 150 degrees Celsius or more 

Four (4) Hose samples with their Maximum Continuous Working Temperature

From Top to Bottom, Synthetic Fiber Reinforced Nylon 70 C°,Steel Reinforced Synthetic Rubber 120 C°,Steel Reinforced High Temp Synthetic Rubber 160 C° Stainless Steel Reinforced (PTFE ) Teflon 260 C°. 

A = Application
How, Where and How often is the hose being used. 
Will it be exposed to the elements, sun, Heat, Wind, Rain, Snow and Ice. 
Abrasive environments such as those found Earth moving equipment, 
Aggressive chemicals, not just those found in paint or industrial chemical factories,
Believe it or not the salt in sea / ocean water can be classified as an aggressive chemical environment because salt when mixed with water and the oxygen in air can deteriorate most materials quite quickly.     

Sea Lift, This Machine Drives down a boat ramp and into the sea and positions itself under large twin hulled boats, it then raises up levels out and brings the boat up onto the shore for repairs and maintenance, it may do this task multiple times a day. 

M = Media,
What type of fluid is going to be flowing through your high pressure Hydraulic Hose? Water, Oil, Gas, Chemicals with what PH Acid or Basic?

P = Pressure
The normal Operating Pressure is very important in ensuring the correct hose is selected for strength and durability. 
Generally we work with an industry recommended Burst to Working Pressure safety factor of 4 to 1. For example a 1/4 inch inside diameter 2 wire braided hose will have a working pressure of 5600 PSI (380 Bar) and have a Minimum Burst Pressure of 22,400 PSI (1520 Bar)

4 Hose Samples with different materials of construction & Working Pressure Ratings. From Right to Left (small to large).

3/8" bore hose Synthetic Fiber reinforced hose SAE 100R6 pressure 34 BAR (500 PSI)

1/2" bore hose with 1 layer of braided steel wire SAE 100R1, working pressure 136 BAR (2000 PSI)

1/2" bore hose with 2 layers braided steel wire SAE 100R2, working pressure 275 BAR (4040 PSI)

3/4" bore hose 4 layers spiral wound steel wire SAE 100R15 ,working pressure 400 BAR (6000 PSI)

E = Ends,
What connections are on each end of the hose. This is Very Important and can vary quite a lot depending on intended application, working environment, how it is positioned and sometimes more importantly on the machine's country of manufacturer or intended country of origin.

Six 1/4" Hose Fittings from Left to Right

14 mm Metric Male,

 9/16" JIC Male,

 1/4" BSPT Male,

1/4" BSPP Female Straight,

1/4" BSPP Female 45° Elbow,

 1/4" BSPP Female 90° Elbow.      

D = Delivery,
How are you or we going to get your hydraulic hose repaired and leak sorted, and what tests and or special safety procedures will we or you carry out before, during and after final installation and commissioning for example ?
  •  Do we come to you?
  •  will you take the hose off and bring to us? 
  • Will you or can you bring the whole machine to us? or 
  • Will we assemble and pack and send the parts to you ready to assemble and install?   
Follow us on Facebook to see all our Daily Adventures & Challenges

The Story is nearly always the same.
 The phone call from the stressed customer is nearly always the same,

I had just one
  • more load to take to the land fill site or
  • more meter of trench to back fill or
  • more driveway to blast clean or 
  • car or boat to rinse off... and I was done!
"But then I noticed Oil or Water leaking and pooling on the ground, or worst yet hot Oil was spraying and making a mess of my engine bay or even worse yet pouring on to my customer's newly cured concrete driveway and freshly painted house wall !?

Sometimes the hydraulic hose leak is small and the oil seeps into the ground unnoticed until your machine starts to shudder and loose power or just stops, moving, digging or grinding altogether.
What The ! you think to yourself !?!

Repairs to Excavator with a Pulverizer,
(a concrete crushing attachment) on a demolition site.

With 50,000 High Pressure Hydraulic Hose Repairs completed over the last 12 years There are a couple of ways to get you back to work.  
The best and safest way is to call us at Mobile Hose Fixers & Hydraulics 
(07) 5571 6155 

Need Hydraulic Hose Repairs click here

However, having a mobile High Pressure Hydraulic Hose Repairs technician visit you is not always possible, practical or economical.  

The quickest and most cost effective way to repair or replace a hydraulic hose will require you to have some mechanical knowledge and aptitude and to be capable of safely finding and removing the damaged or leaking Hydraulic Hose. 

You will also have invested in some minor insurance such as a handful of D.I.Y Reusable Hose Fittings , Hydraulic Hose and some tools such as spanners or wrenches and preferably (but not essential) a  vise or vice mounted to a solid bench or other heavy object. 

If you want some Guidance and insight on how you can manufacture new high pressure hydraulic hose assemblies with basic tools and without expensive equipment? 
Then watch this informative 12 minute video to get an idea what is required to complete a Do It Yourself D.I.Y Hydraulic Hose Repair Assembly using Reusable Field Fit Hydraulic Hose Fittings.

Click here to watch our 12 minute D.I.Y hose assembly Video.

Typical Field Fit Reusable, a Hydraulic Hose Repair fitting used for Hydraulic Hose Repairs and Do It Yourself  DIY hose Assemblies. These two (2) piece fittings screw onto the hose in a certain sequence and once assembled are rated to work safely up to the full pressure rating of the hose. 

If this type of repair seems interesting and challenging and within your technical and physical capabilities, you can visit our web store and select and purchase the parts required.

Click here to Buy Field Fit Reusable Hydraulic Hose Fittings 

For Crimp / Swage on Hydraulic Hose Fittings click here

For 1/4" 2 Wire 5800 PSI rated hydraulic hose

For 3/8" 2 Wire 4800 PSI rated hydraulic hose

For 1/2" 2 wire 4000 PSI rated hydraulic hose

For a complete store overview and everything hydraulic, including, hose, fittings, valves, motors and cylinders. But first please read below to fully familiarize your self and or refresh your memory on the process and parts required. 
If you get stuck or need assistance use the contact us page to phone us or send a message.  

 Click here to contact us

Thursday, February 21, 2019

Why correctly Matching Power Speed and Pump Flow is so important in Hydraulic Lift Systems

The Original title of this blog was 
Warning How Not to Lift a 4200 Kg Forklift Vertically 6 m in 8.5 seconds.

That's moving 4.2 tons at a velocity of 70 cm per second or 2 feet 3-3/4 inches per second straight up.

Just before Christmas 2018, we were called out to investigate and make emergency repairs to a hydraulic goods lift. The 47 KW (60 HP) 2800 RPM high-quality Italian made Elmo electric drive motor designed to operate fully submerged in oil had failed. 

The Motor 
The electric motor rewind shop the motor was sent to told us that it was a catastrophic failure and it was not repairable. They also commented that they had not seen such an unusual motor failure before. The Failure looked like a high amp weld or spark had jumped across the motor casing and into the rotor housing and in the process had burned out a piece of the rotor.  
Further investigations in the new year revealed that a new motor was not available in the country. (Australia). And that a replacement motor would cost Au $13,000 and would take 6 weeks to get here. 

The Pump
The hydraulic pump installed was a beautifully designed high flow Italian S M screw pump and was sized to flow up to 660 Liters of oil per minute at 2800 RPM at a maximum pressure of 40 Bar (590 PSI)

Beautiful Internals of the 660 lt/min hydraulic screw pump.
this pump is for sale contact us below. 

  • A German-made high-quality flow control valve manufactured by Blain Hydraulics.
  •  Click here to see the quality and versatility of this awesome valve 
  • A 2" shut of valve with a built-in emergency lowering valve 
  • A set of large bore hydraulic hoses 
  • A huge gear flow divider 
  • A pair of identical three (3) stage telescopic cylinders.
  • And an oversized 800-liter hydraulic tank. 

The Dramas and the Stresses
I will go into the details at a later date but for all you fluid power engineers and hydraulics specialists out there, our quick fix to get the customer's equipment going again caused us major grief, stress, and embarrassment because..... we assumed that the people who had installed the hydraulic system including the pump and drive motor (and had also inspected it for many years) knew what they were doing !! 
And as our client kept repeating SH*@$#@T the lift has worked without drama for many years!!    

The exposed well of Hydraulic Goods lift with Twin 3 stage Telescopic Cylinders
and Gear Flow Divider between them 

The Quick Fix?

Our quick fix was to rotate the pump through 90 degrees mount it to a new fabricated  support frame and drive it using a new readily available 45 KW air cooled motor using extended drive shaft and solid couplings. So to clarify the Pump is still submerged below tank oil level but the drive motor is dry and out of the oil and is mounted above the tank and is driving the pump with an extension shaft.  

It took us about 4 days to source new motor, frame materials and then fabricate the frame, mount motor and pump, machine up extension shaft and then organise an electrician.

Commissioning Dramas  All went well until commissioning and testing of the new system. The new motor was struggling to power the pump and was just managing to raise the lift frame empty it was also drawing massive amounts of current (the Maximum rated continuous current  of the new motor was 76 Amps and was drawing up to 170 Amps) this high amps was even there after switching from Star to Delta so much so that is was going out on overload. This was quite strange because the old Elmo Motor and the new motor where quite well matched in Power Current draw and RPM. 
The motor was close to overheating and the oil was getting very warm, so a lot of energy was going somewhere??? 

Trouble Shooting
So without thinking it through quite thoroughly enough we thought "something must be wrong with the flow control valve or there is something stuck in it restricting flow" So we bypassed the valve and ran the motor and pump on recirculate, all ran well and with only 30 amps drawn so just to make sure we ran the system for 30 minutes with minimal temperature increases. So I thought It must be valve.

The Valve 
We thought about bypassing the valve and raising the lift with the pump only but thought better not as there was no real way of controlling the flow and speed without a lot of additional hoses and valves and too much risk.

So out the valve came and it was dismantled to pieces,  Did we find anything stuck inside ? No not really, there was some wear and tear from age and contaminated oil ( the entire Blain EV100 valve is made from Aluminium) and a few tired and slack O rings (actually lots of tired and slack O rings) but nothing that indicated a blockage, perhaps we thought the tired O rings where preventing the valve from working correctly so we replaced all that we could reassembled and set up all the default settings and the same thing, High amps, heat and eventual over load.  

I called the electrician he checked and double checked everything and declared all was good something was overloading the motor, we checked the extention shaft and couplings and bearings in motor and pump all OK. 

The Right Way to check a Hydraulic system's design.  

1. Get a pressure gauge and measure the pressure required to raise the lift empty and with forklift loaded on, so I modified a large elbow fitting after the Blain Control valve and drilled and tapped a hole for a standard test port. And then measured the pressures. 
31 bar to raise lift empty, 57 bar to raise lift and forklift.  

The above is done in trouble shooting mode, if designing from scratch you would have to calculate frame weight, payload weights, cylinder bore / rod diameters, pressure requirements and speed requirements and also allow for efficiency losses which can be as high as 40%  to 50% in some instances.

2. Check Pump Specifications as supplied by the manufacturer.
The pump was a Settima SMIT GR70 660 Lt 
according to the specifications this pump at 2800 RPM could pump 660 litres per minute of ISO 68 grade oil at a maximum pressure of 40 Bar. so we had 2 problems. 

  • We did not have enough power for such a large flow pump, according to specifications you would need 55 KW at 45 Bar but we needed 57 Bar and we only had 45 KW
  • Also the pump was the wrong pressure rating as it was only rated for a maximum of 40 BAR and we needed 57 bar to raise the lift frame and forklift. Further research indicated that to achieve 57 Bar at 660 Lt/min we would need a least 78 KW.
  • For the above reasons we recommended to the customer to change out the pump with a smaller flow, higher pressure to more closely match motor power available. With costs and time by this stage were blowing out we eventually chose a GR45 180 Lt this pump at full 80 bar pressure would only require 30 KW

Below is the full report of our findings as reported to the customer after a few days of testing, head-scratching, number crunching and research. 
The Blain Hydraulics online Lift Calculator was a great help in getting the customer to understand the situation and to also reinforced our findings research and calculations. 

For privacy reasons, I have removed all mention of the customer and location. 

Summary of Findings, Damaged original Drive motor & poor performance of replacement motor at XXXXXX ... XXXXX.

  • Calculated weight of empty lift is approx. 2200 Kg
  • Add 2000 KG for Forklift total weight 4200 KG.
  • The pressure required to raise empty lift = 31 Bar (450 PSI)
  • The pressure required to raise lift with forklift = 57 Bar (850 PSI)
  • The installed pump is rated to 40 Bar (57 bar required to raise lift and forklift)
  • Originally installed Pump Drive motor was rated to 47kw at 2770 RPM and 89 AMPS. 
  • New motor rated at 45 KW at 2960 RPM. (%7 higher speed) at 76.3 amps.
  • Power required to raise empty lift 45 KW
  • Power required to raise lift with forklift only! Is 81 KW.
  • Option 1 replace 2 pole motor with 4 pole motor to reduce speed to 1450 RPM.  However, the pump is working at 40% over the maximum rated pressure. And may not last long term.
  • Option 2 Best long term fix, source smaller pump rated at the correct pressure and installed motor speed.

·       Please see full calculations and pictures below.

·       Figure 1. Name Plate From Original Elmo Damaged Drive Motor 47 KW (64 HP) at 2770 RPM Max running amps 89 A
Figure 2. Name Plate From Replacement Techtop Drive Motor 45 KW (60 HP) at 2800 RPM Max running amps 76A. 

 Figure 3. Installed pump in tank, Specification is as follows
S M Screw pump GR70 –SM-660 LT
this pump is rated to only 40 Bar, 57 Bar is required to raise lift frame and forklift only.  

Figure 4. The Installed high Flow Pump requires 81 KW at 2960 RPM to flow 660 LT / Min.
It Requires 41 KW at 1450 RPM to flow 330 LT/Min.  See calculations below. 

Figure 5. Full Calculation Based on Actual Measurements  & Calculated Data. Motor Power required is 81 KW. Actual installed power before failure was 47 KW. Hence the catastrophic failure of the submerged electric motor after years of short duration high amp operation. 

Conclusion, today we are replacing the 660 liters per minute 40 bar pump with a higher pressure (80 Bar 1100 PSI)  pump rated to flow 180 liters per minute at 2800 RPM.
We will leave the new 47 KW, 2800 RPM replacement motor in place. 

When complete this installation will be capable of raising the lift superstructure, forklift and a ton of payload (total of 5200 Kg ) to the next level (6 meters up) in a little over 30 seconds.

New high pressure 180 Lt/min pump on left with old low pressure 660 Lt/min Pump on right. Bernardo our always smiling hydraulics technician working on the changeover.  

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