Recent content by frogcurry

Don't forget to revisit all pressure relief (fire, blowdown, burst tube/ tubesheet rupture) calcs in light of the design pressure change if you proceed with this.

What jcaiken says is correct as I understand it. the Institute of Petroleum has some guidance published on this. For the relief backpressure, the line/ disk sizing methodology is based on the backpressure produced by the slug of seawater pushed ahead of the expanding gas, as per API 520/521.

If a centrifugal compressor has its discharge blocked in then it will recycle at its anti-surge control point. Flow isn't zero.

If sizing for relief valves lifting on blocked outlet, then the gas relieving from compressor A can't be also simultaneously coming out compressor B, if the order is A>B>C in series. Since after all blocked outlet on A is blocked inlet on B. Its not feasible to have A and B both pushing open...

Effects of pressure drop depend on whats in the tubes and conditions... If you want to use a program to design heat exchangers use HTFS-TASC. Or buy a book.

Ahem... that theta is of course an angle of convergence in Crane, so the 60 degree theta is for a 30 degree slope on the wall.

After reading your last post I did some quick analysis in Excel of this using Cranes method for gradual reducers as well as sudden reduction: const beta factor result Crane 0.5 0.75 1 0.375 ISA 0.5 0.5625 1 0.2812 2-13 0.8 0.75 0.258 0.1552 2-13 refers to the...

The ISA eqn quoted above is just for the inlet reducer.

Use the Shell DEPs if you have them.

ISA S75.01-1985 quotes for an inlet reducer (Eq 6, pg 15): K1 = 0.5 * (1 - (d^2/D^2))^2 Crane 410M page 2-11, eqn 2-10 quotes K1 = 0.5 * (1 - (d^2)/(D^2)) These would appear to be equivalent concepts but there is a difference - ISA quotes an additional squared at the end of the eqn. So, am I...

Hi, I'm attempting to assess (at a preliminary stage) whether a vacuum pump system (liquid ring pump and ejector operating in two stages) is adequate for an increase in duty in the seawater flow. I have a pump curve for the liquid ring pump but no other information. It gives a curve of torr...

Please clarify - an orifice for going from 3 psig to 1 psig or an orifice to go from 5 psig to 3 psig? Whats your intended downstream enduser pressure?

Thanks. What you describe is exactly the sort of scenario that the Loss Prevention Bulletin describes save that the pressure differential driving the pig was on the order of 400 psig for a 12 in pig... When you're doing this do you have any estimation techniques you use for assessing how fast...

This is a tricky question to define as its not a specific item or system, but a generic concept. While reading the Loss Prevention Bulletin article this month on pigs, I read a comment about "20 tons of force" driving a pig out of a pipeline which had its pig reciever open causing the pig to be...

The LPB article referenced by cawse001 is a very good place to check, particularly for the design of proper depressurisation locations.