Installation of valves at suction and discharge side of pump. 5

[Abhi1712]

Hello everybody,

Can you please tell me what kind of valves should be installed at suction and discharge side of centrifugal pump in general practice?(by considering friction losses)
Pump details: Crude oil transfer from tank1 to tank2, Suction side pressure-10 psig with 4" nominal size pipe, discharge side pressure-110 psig with 2" nominal size pipe.

 

[BigInch]

Tank to tank, assuming no pressure control required and these are for isolation of the pump only, they would normally be a full port ball or gate valve.

 

[cvg]

check valve is normally installed to prevent backflow from tank 2 to tank 1

 

[omereada1]

Suction piping should be at least one size larger than the suction flange at the pump.
If increasers are used on the discharge side to increase the size of discharge piping, they should be installed between the check valve and the pump.
Both a check and gate valve should be installed in the discharge piping with the check valve placed between the pump and the stop valve to protect the pump from reverse flow and excessive back pressure. Manually operated discharge valves that are hard to reach should have some facility for quick closing.

Suction piping must be kept free of air leaks.
The installation of check valves should be avoided in the suction piping although they are often used to reduce the number of valves that have to be operated in switching between series and parallel pump operation. Do not use globe valves on the suction except for throttling if desired.

Henri Onuigbo (Chartered Engineer).

 

[racookpe1978]

Add vent valves at the high spot (both sides of the pump), drain valves at the low spots. Get with your I&C engineer to find out what instruments are required.

So, now you have a fluid that can be pumped from Tank 1 to Tank 2. I need to pump from Tank 2 to Tank 1 for an inspection and servicing of Tank 2. How are you going to let my oil flow? 8<)

 

[BigInch]

2 tank bidirectional, see att.

 

[waterpipe]

Talking based on the water sector (I know there might be differences with the oil and gas sector and hopefully others will mention them to have a side by side comparison):

Suction line moving from tank to pump:
BV (Butterfly Valve needed for pump service)+ DJ (dismantling joint)/ AV (Air valve) and Drain valve might be needed at the end of suction main if you have several pumps in parallel.

Delivery line moving from pump: Check valve+DJ+BV / AV at drain valve at the end of the main line again if you have several pumps.

you might like to have a flow meter (oil is pricey these days)on the main line.

 

[BigInch]

"Crude tanks". Oil & gas preference is usually to only meter on change of custody (money) points, unless there is a specific process reason (usually not the case at tank lines). Also in oil/gas ball and gates are preferred for their more reliable positive shutoff during pump maintenance. Check valves not needed for backflow with positive shutoff valves and especially with the same product in both tanks. If there was an issue there, a double block and bleed valve would absolutely guarantee that there would abe no crossflow.