Recent content by Drexl

EN 1983 (it is table 4 in the 2006 issue)

EN 1983 specifies the minimun diameter of ball valves per DN-size/pressure class. The listed valves are all full bore.

It will move until the forces equalize.

I can't really think of what kind of application this would be, are you sure you describe it correctly? In your example, if you have 120C at the outlet (at atmospheric pressure at equilibrium) you must have pure steam and it is not possible to supply that much heat through such a short pipe. If...

As XL83NL says EN 13445 is harmonized to PED and used for unfired pressure vessels. EN 286 is harmonized with SPVD and used for simple unfired pressure vessels. It covers smaller unalloyed steel and aluminium vessels with a pressure of max 30 bar for air and nitrogen. The exact scope of the...

As I remember the standards state that calculation has to be done on the higher of the tube/shell side temperature unless a lower temperature can be justified. If you proteect the tubeside using a switch as golpesar88 suggests, this switch is a protection function of a pressure vessel and has to...

I see I was a bit unclear in my post. There is of course steam exhaust pipe and a liquid drain pipe. During normally occurring operating cases sufficient separation will take place. It is however possible to have all valves draining to the tank simultaneously giving extreme flow to the tank. The...

Calculate the pressure drop in the outlet pipe and there you have your maximum pressure. Select design pressure accordingly.

Latexman, thanks. I will review this. There is quite a lot of literature similar to this that investigate mass flows from pipe breaks connected to the pressure vessel of nuclear reactors. The problem is that they have high pressure and usually saturated liquid at inlet. The translation to my...

No process engineers out there?

Hi, I was wondering if anyone know a proper pressure drop correlation for 1. Low quality steam x=0.1-0.3 2. Low pressure 0.2-1.5 bar(a) I have a flash tank connected to the condenser by a short pipe. At a disturbance case I expect extreme flow to the tank and would like to calculate what the...

Hi, If your problem is selection of design temperature, have you considered that the fan might trip and you blow 200°C through the heat exchanger?

I didn't even know there were plants where you don't number your equipment :) I don't see how numbering the valves can be much more work than painting them. That is the first key to having proper operating instructions.

Hi, I'm looking for comprehensive and modern literature on power plant water chemistry. Anyone have any suggestions? What i'm looking for: -History/evolution of water treatment -Used treatment programs -Used chemicals -Description of mechanisms - stress corrosion cracking, FAC, pitting, erosion...

Generally you can combine outlet, see for example EN 764-7 ch 8.2.3. It shall be shown that the back-pressure doesn't prevent the operation of the safety valves as described in previous posts. The conservative and often correct way to size the outlet is then to assume that all valves are...