1.Lets assume H50 valve has a problem with an internal leak.

2.Pumps the system upto 0mbar with the N2 manual valve the N2 open. However, H2 gas flow should be cut off.

3.Refill the system with N2 gas to ATM

Adjust the amount of the flow to lower level with the regulator.

☞ When the falulty valve are replaced with new one without N2 gas comnig out, the external air is bound to get into the joint parts, having determintal effect on the tubes, in terms of conermination to the tube inside. However, with the N2 gas coming out from the openings, the contermination can be prevented.

Replace the faulty valve with new one.

☞ Remove all the exising gasket on the openings and place new one. ☞ Be careful not to place the gasket on the existing gasket.

5.Pump the system out to 0mbar to check if there is an external leak on the joint parts

Upon confirming the reactor pressure reaches 0mbar, conduct leak check from N4 manural valve.

☞ By connecting the detector to N4 manual valve, unnessary tubes can be isolated. All the tubes is not necessary to be pumped out since the only thing required to be checked for the external leak is H51.The external leak check is quite time consuming. In order to save time, N4 manual valve would be good choice to be connected with the detector.

☞ As far as the used machine concerened, the leak rate would not be decreae at the fast pace. In this case, the 25mbar check valve can be put down to the cause since the check valve doesn’t close the openings properly, letting the gas come into from exhaust tube.

Yes, there are "mistakes" in grammar.

But there are also phrases in which the intended meaning is not clear. This makes it difficult to correct the grammar.

Could you use "fittings" in place of "joint parts"?

Is there only one gasket?

What is "H51"? Another valve? Check it for what?

By "internal leak," do you mean the valve does not fully close, or that it leaks to atmosphere?

Please define "Ombar" and "ATM."

"1." is not actually a step.

There's no "step 4."

Is one check valve supposed to close multiple openings?

Letting the gas come into WHAT from the exhaust tube?
thank you for reading my stences.

here are my answer.

yes, there are fittings to connect valves to tubes.

If the valve has two inlets two gasket are used.

H51 is a vlave. I have to check it if there is a leak or not.

Internal leak means it doenst fully close. It doesnt leak to atmosphere.

0mbar is a pressure. 0mbar is a vacuum state.

ATM is atmosphere.

letting the gas come into the openings.