10 tips on how to best maintain hydraulic pumps
1. Check the oil level in the tank before use - measure from a horizontal surface.
a) Fill the oil tank exactly to the level mark.
b) Change the hydraulic oil regularly - at least once a year.
c) Use hydraulic oil with the correct viscosity. On Holmatro products, the optimum viscosity is 36. When you want to use the Holmatro pump at temperatures below -10 °C, you must replace the hydraulic oil with a hydraulic oil with a viscosity of 15.
2. When using engine-driven hydraulic pumps, check the fuel level before use - measure from a horizontal surface.
a) Ensure that there is sufficient fuel in the tank to prevent sudden engine failure when using the hydraulic tool.
b) Fill the fuel tank to the specified level. Never overfill when aerating.
c) Never add fuel when the engine is running.
d) Do not use dirty fuel and ensure that no dirt, dust or water enters the fuel tank to prevent damage to the engine.
3. Use the right type of hydraulic pump. Not all pumps are suitable to be controlled by all kinds of hydraulic tools. It depends entirely on the oil volume and the number of valves. Use a pump with sufficient oil volume (tank content) to check the tools.
The minimum effective volume of the pump = (oil content in cylinder 1 + 2 + ...) x 1.2 (safety margin).
Choose from hand, foot, air, electric, gas or diesel powered pumps:
a) Hand/foot pumps: suitable for smaller hydraulic tools such as a cylinder. With a double-acting tool (hydraulic return), a double-acting valve must be fitted to the hand pump.
b) Motor pumps: depending on whether the tool is single- or double-acting, a single-acting or double-acting valve must be fitted to the motor pump.
4. Always connect both couplings on the pump with a double-acting tool.
This allows a flow of incoming oil and a flow of outgoing oil. The principle behind a double-acting or hydraulic return tool is that the piston's retraction and extension is controlled by oil pressure. On the stroke of the piston, the incoming flow of oil passes through the lower coupling into the lower chamber of the cylinder housing and this pushes the piston upwards. Oil in the upper chamber must return to make room for the incoming oil. This outgoing stream of oil passes through the upper coupling into the tool back to the pump. The oil flow process is exactly the opposite of the piston stroke. If the pump has only one coupling, it is not compatible with a double-acting tool.
5. Always screw the coupling tight by hand until you cannot see the thread between both coupling halves. Do not use wrenches or other tools to further tighten the couplings. If you cannot tighten the coupling sufficiently by hand, it is possible that the threads are damaged or there is residual pressure in the hydraulic system.
6. Avoid damaging the system.
a) Protect all parts of the hydraulic system from sparks when welding or grinding - to prevent leaks.
b) Never lift the pump using the coupling or the hose. Always use the handle or eye fitted for this purpose.
c) Avoid damage to the hydraulic hose that occurs due to kinks, knots and pinches. Such damage may cause leaks.
7. Ensure that the pump is placed on a stable surface so that it cannot roll or tip over during use.
8. Always release pressure from the system before disconnecting the hose or tool. This allows the couplings to be unscrewed by hand and at the same time prevents residual pressure from remaining in the system, which can have harmful effects during subsequent use.
9. Keep the system clean.
a) Avoid dirt in and on the couplings. Screw the clutch dust caps together before using the system and clean them afterwards.
b) Painted as well as plastic and rubber parts are not resistant to corrosive acids or liquids. Use plenty of water to rinse all parts that come into contact with strong acids or liquids, except electrical components.
c) Dry the pump thoroughly after it has been used in a wet environment. Apply a thin coat of preservative oil to the white or black parts to prevent rusting.
d) Store the pump horizontally in a dry and ventilated room.
10. Carry out regular maintenance of the pump and ensure that the pumps are inspected every 12 months by an expert - just like all other lifting equipment.
See products from this product category in use:
Johannesen Kran & Maskintransport has had a unique job in connection with the metro construction in Copenhagen; a load-bearing ceiling structure had to be raised the decisive 10 mm, so that old beams could come out and new ones in. But how do you do that when the building was both old and crooked? The solution was a complete package of products from this product category, which was used to create the necessary space for replacing the load-bearing beams.
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