FCH
HYDAC
BOSCH
NACOL
CHINA Make
Greer
Also EPE Make.
Super high pressure nitrogen filling up to 200 bar of any make accumulators is undertaken at our service centre with the most sophisticated equipment.We undertaken annual maintenance of hydraulic accumulator of any make which include pre-charging of Hydraulic Accumulator with Nitrogen Gas and Spares.
Before installation it is most important to ensure that the gas pressure corresponds to the desired value. The initial gas pressure must be selected to meet the service requirement.In general the design values are as follows: P = 0.9 P , ( energy reserve, line shock absorber, etc.) P = 0.6 - 0.7 P ( pulsation damper )
Gas recharge pressure is of crucial importance to the correct functions of the accumulator and the durability of the bladder. The gas pressure, when the accumulator is supplied pre-charged is related to the temperature of 20°C. In the case of accumulators supplied without pre-loading pressure, or after repair work it is necessary to perform inflation with nitrogen; must also be performed also the verification of the system by using the equipment type-PC following procedure checking & charging
Before the system is pressurised it has to be bled. For this, the event screw in the fluid port assembly has to be eased until fluid emerges. Then retighten the gas valve locknut carefully. The system is charged with maximum pressure and sealings and connections should be checked.
After the installation of a new unit,or following repairs, the initial pressure must be tested as follows: Atleast once during the first week so that any gas losses can be immediately observed and remedied. If no gas losses are observed during the first check,a second check should be carried out approximately 3 months later, If during this check no gas losses are evident, a six-month check should be sufficient. It is however recommended that heavy duty applications be checked every month.
Pre-Loading & Checking Set type-PC (refer Fig.16) is to be used for checking / charging of Bladder Accumulators. When charging, the nitrogen bottles must be capable of delivering pressure higher than the desired accumulator gas pressure. Use dry industrial nitrogen. NEVER USE OXYGEN OR AIR. Proceed as follows :
- Fit the suitable pre-charging equipment to the gas valve; - Connect it to the nitrogen cylinder with the charging hose; - Slowly introduce nitrogen into the accumulator until reaching a pressure slightly above the required level; - Close the valve of nitrogen cylinder and disconnect the charging hose from the equipment; - Wait for the gas temperature stabilization; - Set the pressure by venting off the excess of gas.
It is important that the gas pressure be kept constant and should therefore be checked periodically by means of the filling and checking equipment PC/... The same equipment is used for re-inflating the bladder after repair work or change of use. Connection is made by the special hose to the dry nitrogen bottle.
This is simple operation, the correct procedure is as follows : Isolate the accumulator from the system and reduce the liquid pressure to zero. Remove the protective and sealing caps from the gas valve. Prior to the mounting PC/ - equipment ensure that the valve A is unscrewed, that bleed valve B is closed and that is non-return valve C is screwed tight. (refer Fig.17) Attach the unit to the gas-fill valve by means of the knurled nut D.Screw valve A to a point where pressure is registered.If the pressure is OK remove the PC/unit as follows : Unscrew the valve A. Open the bleed valve B and unscrew the nut D.
If the pressure has to be reduced this is done by opening the bleed valve B slowly until the correct pressure is registered on the gauge.
If it is necessary to fill, or to increase the gas pressure, proceed as follows: Fit the PC/ unit as described above. Fit the connection to nitrogen cylinder. (refer Fig.17 & Fig.18) Connect the hose between the cylinder and the non-return valve C. Slowly open the valve on the cylinder till the gauge registers a pressure slightly higher than the one desired, then shut. Unscrew A and reduce the pressure PC/ unit to zero by means of the bleed valve B. Disconnect the hose from the non-return valve C. and replace cap. Close the bleed valve and wait approximately 5 mins. for the temperature to adjust. Screw valve A until the pressure can be read. This should be slightly higher than the desired pressure. Adjust by means of bleed valve, remove the filling unit. Use soapy water test for leaks. Replace the valve cover and protection cap. The accumulator is ready for use
At G.M. Engineers we offer an unparalleled level of customer service and set industrial standards to enhance supply chain effectiveness, quality and competitiveness.
