[b]Check valve on Discharge Pump[/b]

[13392017]

Hello All,
We have project to design some Pressure Testing Unit using high presseure air driven pump(15KPSI). On brainstorming session we have two opinion about check valve installation on discharge outlet of High Pressure Pump. One said said mandatory and the other side said no necessary.

Please, if somebody in this forum could help us to make a good decision about the necessity to install check valve on discharge outlet of High pressure Pump.

Best Regards

 

[quark]

Not necessary if it is a positive displacement pump.

Regards,


Eng-Tips.com : Solving your problems before you get them.

 

[13392017]

Quark,
Thank you for your quick respons. The reason why the people want to install the check valve, is to hold the high pressure. The pump should be free from this job.

But when i see the construction of the high pressure pump, the check valve already installed in the discharge outlet.

I have no idea how to explain the people about this.

Thank you

 

[Jalink]

If I understand the question correctly, this is about a really high pressure application (15 000 psi), where the pump has to be freed (isolated) from the discharge system leaving the discharge system pressurized and the pump without pressure. Assuming you are talking about a positive discplacement pump of the plunjer or membrane type.

It appears to be ambigious to rely on the pump discharge valve(s). Discharge valve(s), as also check valves, have the habit to leak. To block your pump, a valve seems to be the appropiate method. If the pump has to be really "freed" a block and bleed should be considered.

 

[13392017]

But, is it necesary to use the valve (isolated valve) ?

Regards,

 

[Jalink]

13392017, it is difficult to answer your question in full. Quark can be right, pending on the application and service of the pressure testing unit.

Pending on the location where the unit will be sold and/or put into service, analysis of HAZOP, safety and risks should be performed considering the operation philosophy, as it should be specified in the installation, operation and maintenance manual, taking into account possible foreseable abuse. Attention should be paid to the energy stored in the pressurized system and the consequences of leakage through the discharge valve.

If such a review does not conclude in the requirement for blocking means, additional the pump discharge valve, which is normally a single check valve suitable for the pumping action, one does not require additional valves.

Regards,