The accumulator is an equipment which stores the hydraulic energy by utirising the highly pressurised gas.
The handling manual shows the various requirements for using the accumulator in safety.
Regarding three symbols of handling manual, if you ignore them and adopt the wrong method, it will cause
the explosion of the accumulator and/or injuries.
So before using the products, read through the handling manual and operate the accumulators correctly
with safety in mind.
1. Accumulator
Notice to be paid when Accumulator selection is made.
Select the suitable accumulator matching with the specification of usage such as the max. allowable working pressure,
the allowable oil flow in/out speed, the operating fluid, the operating temperature, the working
environment, and the applicable regulations.
Especially, in case the application of usage is either for Shock Dampening or for Pulsation Dampening,
select the accumulator which covers the max. shock pressure or the max. pulsation pressure these occur
when the accumulator is not installed.
Notice to be paid when Accumulator is installed.
Do not weld, cut, or grind any parts of the products (except the welding flange).
There is the possibility to explode the accumulator shell and it is very dangerous.
If the accumulator is hung using only a coiling wire or rope, this may result in the accumulator being dropped.
The hanging tool is equipped as the standard to all accumulators which weight is more than or equal to 20 kg (as of April, 2010).
Also, if the SG valve is installed to the accumulator, please remove it and use the hanging tool to hang the
accumulator.
The accumulator shall be fastened properly with plural clamps. If the accumulator moves or vibrates in the different direction to the piping or stand, the piping and/or the connection area between the accumulator and hydraulic piping may be damaged. If the accumulator is not fastened properly with plural clamps, the piping and the connection between the accumulator and the hydraulic piping may be damaged in event of an earthquake or abnormal stress or vibration. After adjusting the axial lines of the Oil Port Valve Assembly and the hydraulic piping on the straight line, connect the accumulator body and the piping, and fix them in a way that the excessive stress cannot be applied on the each connection parts.
Install a pressure relief valve in the hydraulic circuit which will use the accumulator so that the hydraulic service pressure may not exceed the max. allowable working pressure of the accumulator and its fittings.
Notice to be paid on the System Requirement.
Be careful to the system environment (heating and corrosion, etc.) where the accumulator is installed.
If the accumulator is heated, there is the possibility that the accumulator will be damaged by the highly pressurized
nitrogen gas becoming higher than the max. allowable working pressure due to the temperature rise.
Under the corrosive environment, the accumulator may be corroded and threaded area is damaged at the time of
the system pressure rise.
Notice to be paid at Gas Charging.
Charge the accumulator with dry nitrogen gas only. There is a possibility of causing the explosion if the combustible gas such as the oxygen and/or the air is charged to the accumulator.
Before using the gas charging hose, confirm that there is no deterioration such as crack or the damage on it.
It is dangerous to use such deteriorated hose as there is possibility of the hose bursts during gas charging.
Take care that if you turn the valve opening-closing handle of 3-Way Valve or the bleeder valve handle too much using
the tools, it may cause damage to them and high pressure gas may blow out.
It is good enough to handle Set Nut and/or opening-closing handle by hand.
Notice to be paid during disassembling.
When doing Accumulator disassembly, stop hydraulic system first, then relief the circuit pressure, and discharge Accumulator nitrogen gas completely, beforehand.
When the nitrogen gas is discharged from Accumulator, ventilate the air well to avoid anoxia.
Also, confirm the gas discharging direction and no people there and/or no danger estimable in that direction.
There is a possibility to get injured by the strong power of the discharged gas.
Notice to be paid during assembling.
Before start assembling, check that there are no abnormalities (rust, crack, corrosion, deformation etc.) in each part.
Also, confirm if the shape of screw (standard, nominal diameter, and pitch) is suitable.
Notice to be paid when discarding.
When discarding the accumulators, completely discharge all the nitrogen gas and fluid to the atmospheric pressure so that no pressure remains, and then disassemble all parts. Destroy the threaded part of disassembled parts so that the parts cannot be reassembled. After making sure that they cannot be reassembled, discard them.
Do not incinerate the bladder because there is a possibility that the incineration of the bladder generates poisonous gas.
Discarded bladder will have to be cut in small sizes to meet ordinance relating to the managing and cleaning of waste.
Then request the appropriate waste handler to discard them.
2. SG Valve
Do not use the tools to the opening-closing handle of SG Valve or the relief valve.
Take care that if you turn the opening-closing handle of SG Valve or the relief valve too much using the tools,
it may cause damage to them and high pressure gas may blow out.
Check the appropriate torque on the handling manual.
During operation of the accumulator, V1 Valve of SG Valve shall be kept open all the time.
If V1 Valve is not opened, the fuse plug or the spring loaded type safety valve will not work.
3. Spring Loaded Type Safety Valve
When the spring loaded type safety valve were installed on other valve than SG Valve, consider the safety at maintenance time and design so that the internal gas pressure can be relieved from the piping.
