100% usually refers to the quantity of valves RT'd. For example it is typical to RT 10% of CS valves CL600 but the same project could require 100% of SS valves CL900 and above to be RT'd. The percentage is of each valve size and type.
2" and below are normally DP tested because they're...
The valve body (and bonnet if it is top entry) and stem are pressure retaining and require to be supplied per NACE.
The ball is not pressure retaining and not strictly required to conform to NACE. Of course if it is closed for long periods the face of the ball will be under pressure and this...
I think you are exactly correct, however, it is very difficult to design the discharge system to match the calculated frictional loss exactly (unless you can vary the elevation). Normally you would use a valve to trim the system pressure drop to match your desired outlet pressure/flow.
rmw: I apologize if my post was offensive to you. I thought you were answering the posed question.
JimCasey: I used to have your faith in valve application engineers (I was a valve application engineer for Masoneilan and Fisher many years ago) and I'm sure if you work in Houston, London or...
PaoloPemi, I agree that you can get different vendors to size 2-phase flow for a sizing check but make sure your process engineer does a flash calc to check the vapor/liquid fractions. Many times the vendors overestimate valve Cv due to flashing. The effects of subcooling also reduce the...
Renoyd, your question is incorrect. The downstream pressure is 10psig. The valve flashing calculation does not affect the downstream pressure.
Imagine you were discharging to atmosphere. Downstream pressure is 0 and will always be 0. Like JimCasey mentioned; the effective pressure drop...
In the refining and O&G production industry, exposed bolts can expand and be a leakage risk during a fire.
A wafer type is therefore only installed in flammable service if protected by rigid fire insulation.
Lug type valves are used in end of pipeline service.
Lug types can be threaded or with...
There are no free sites I am aware of. Ask the client for a vendor list of cable suppliers to GOST.
I am not sure what you mean by "from GOST to API". If the cable is going to Russia then it must meet the GOST requirements and should be purchased as such.
It is more expensive to buy the...
You can also check to see if the downstream piping diameter is large enough. Since the diaphragm pump has instantaneous acceleration you can't use the nominal flowrate to determine required pipe size. There's a small chance the piping friction loss is sufficient to push the pressure above the...
JL Seagull: we install the downstream triple offset butterfly valve in a DB&B installation backwards for isolation if downstream will be pressurized.
They are bi-directional with a preferred pressure direction and the actuator thrust requirement is less for shutoff in the preferred direction.
1. The flow will be sonic, not supersonic.
2. The noise of 90dBA can be mitigated by heavier wall piping downstream and/or insulation if lo-db trim is deemed undesirable.
3. Depending on flowrate, a v-ball with diffuser could reduce the noise below 85 dbA. If flow and pressure drop are constant...
Impulse lines may be purged to have a velocity of 1 fps (you are just trying to keep dust out).
The pressure upstream of the RO should be sufficient to ensure critical pressure drop (roughly twice the outlet pressure) but it may be higher if desired so I'd set it at, say, 12 psig.
Calculate the...
If a control valve will see vacuum under all process conditions then you can install V-ring packing upside down.
If the valve will see both pressure and vacuum then you can install "double packing" where half the chevron rings are inverted.
I recommend bellows if air will contaminate the process.
