thanks littleinch
anyways im gonna be collecting the process data but what i dont understand is do i collect the desired flow rates and corresponding pressures from pump curve or actual flow rates and their corresponding pressures form the field? because i have seen some data sheets where the...
Thank you littleinch as always you're the first to reply with logical answers which I appreciate. Can you elaborate on angle to horizontal?
Thank you trueblood yes so the slope is the Cv which is fixed in this pic. But if control valves have variable Cv then why do we calculate one value of Cv...
Dear all,
how do you reconcile pic1 with pic2. Pic1 shows that at low flow (minimum flow) the DP across the control valve is high whereas in pic2 low flow is proportional to low DP across the control. can anyone please dispense my confusion over this ? thanks.
i mean the DP in the valve sizing equation (p1-p2) is DP across the valve only and not the total pressure loss of the system. valve DP is only a fraction of system DP.
i have a gate valve that is throttled that i want to replace with a control valve.
ok so the gate valve i was telling you guys about is located on Pump A's discharge and it is somewhat throttled when pump B is off . So now when pump B comes on, the supervisor runs down to pump A's gate valve and opens it fully then everything goes back to normal with respect to the two pumps...
attached are the pump curves
elevation is flat
final destination is a tank
the supervisor mentioned that every time pump B came on line he had to physically go to the site and throttle a gate valve to keep pump A working. I'm not sure where the location of that valve is on the lines. I'm...
limiting conditions are
pumps can't be replaced too expensive
line cannot be made bigger too expensive
even separating the lines might not be done due to cost
is there a simple fix ?
so you're syaing if i throttle pump B just enough not to trip it that would lower the system pressure on...
yes both pumps are centrifugal
data taken from pump curves:
BOP:
pump A Data is: 350 gpm @ at 370 ft head
pump B data is: 1225 gpm @ 295 ft
I believe the system curve intersects at the above points.
pump A trips on a pressure switch
fluid is oil but the pump design utilized bernoulli's...
Dear all,
Whenever Pump B comes online, pressure on Pump A goes up and trips it. is there anything that can be done to resolve this? both pumps need to be working simultaneously.
thanks.
dear all,
we have a tank with the following 2 problems:
1. huge gap between bottom plate and the tank foundation
2. nozzle misalignment
does anyone have any experience with this??
also what is the tolerance for bottom plate slope as per api code??
The b31.3 code is a design code not a manufacturing code so its test pressures are are going to ve understandably much less than let's say api 5l. Even api 5l is at 60% or 70% SMYS. I think the intention of b31.3 pressure testing is to verify the workmanship or integrity of the weld not the...
In one of the interpretations of the code,namely Interpretation 21-11, it says that a pressure test of less than 10 minutes by the pipe manufacturer will not satisfy b31.3 code requirements of paragraph 345.
Also the purchase order for these spool stipulates/additionally identifies b31.3...
Hello gentlemen,
Apologies for this belated response it's the weekend here. So just to answer some of your questions again:
- I already asked the supplier to submit a more detailed procedure on pressure testing and whether he will be using end stops/plugs/weld to connect and seal off the ends...
Hi gentlemen,
Just to answer the questions above :
- our service is normal fluid service not category D.
- the reason we request even flanged end spools to be hydrotested during their manufacturing even though we can just hydrotest the completed system once during field erection as per 345.2.3...