safety valve position in steam turbine

[geliberman]

I am going to design a steam driven pump piping.
is that possible to install the safety valve after the gate valve in turbine exhaust?
We have not enough area to install it before gate valve.
Thank you!

 

[Duwe6]

If you have the gate valve *locked* open,and

if the key can only be accessed by management and/or the Watch Operator-in-Charge of the turbine and is only used knowingly and in accordance with a written procedure, and the valve closure shown in the boiler 'Run' logbook, and

if the valve is never closed during operation OR an Operator is stationed on the turbine at the closed valve 100% of the time [NO bathroom breaks], in full communication with the control room [or with a view of a certified pressure gage] and is able and *willing* to vent the turbine if it tries to overpressure,

then it is acceptable to have a valve below [inboard of] a Safety Relief Device. They are normally connected directly to the boiler/turbine [no interviening valves] for a damn good reason.

 

[racookpe1978]

I'm going to disagree strongly (!!) with that proposed location: No turbine I've ever worked on has been rated for the boiler/piping safety (relief lifting) pressure of the boiler, steam piping and feed piping. The steam HP inlet and first stages are designed for HP steam FLOW at tremendous energy and at high pressures and temperatures, not static pressure.

The steam expands through the stages, looses energy and cools somewhat, and exhausts into a condenser with a vacuum below the tubesheets and (at best) only a few psig (half-bar guage or less) at the upper expansion joint, and a high vacuum below. In addition, various feedwater heaters or moisture separators are attached at mid-points on the turbine casing. Turbine seals, controllers and systems are rated for the pressures at the normal operating conditions; NOT HP steam pressures at boiler relief valve pressures.

You're trying to claim that nowhere in the boiler and steam piping can you fit a single steam pipe and a single connection from that point to a simple pair of safety valves?

Nonsense.