CSA for Canada in Turbine Fuel Shutoff Applications

P

Thread Starter

Paul Brock

Hi Guys,

I am new to this forum but hoping someone can help me out.

I am trying to spec out a solenoid valve for fuel isolation on a gas turbine. The fuel media is heated and to a high pressure & bore size. The issue I have is that the types of product that I am looking at do not quantify the standards which they adhere to within the CSA Canada codes.

Many specifications state "certified to CSA for Class I, Division 1, Groups C & D, T3 and Division 2, Groups A, B, C, & D. Now from my understanding, this typically is conforming to 'general purpose valves' within CSA 139.

part of CSA 139 states for safety shut off valves, they must also conform to CSA 6.5 C/I (ANSI Z21.21).

My question is:
Do valves for turbine fuel isolation have to conform to this separate annex CSA 6.5 C/I (ANSI Z21.21)?

I am not looking for direction to a specific manufacturer but clarification of the requirement for such application/standards. The additional CSA 6.5 C/I (ANSI Z21.21) looks like it is for burners rather than turbines but it is quite ambiguous and no manufacturers of shutoff valves advise the additional standard so I assume even in a safety fuel shutoff valve they do not conform?

The additional test requirements for CSA 6.5 C/I (ANSI Z21.21) look like high cycle fatigue test specs (100,000 cycles) but are they really relevant to applications which are in such low demand (1 cycle every few months/a year)?

Clarification around this issue is much appreciated.

Many thanks,
GT_Brock
 
As an electrician, I would look to the code book, specifically hazardous locations, as you have. I would hazard (no pun intended) that a valve that meets the hazardous location requirements should be well documented by the manufacturer, and they should be able to answer and verify what other specifications it meets. It seems to me if it is a shut-off valve (satisfying the CSA 6.5), it should be hazardous location rated (satisfying the Code requirement). Perhaps one implies the other, so only the Code requirement is listed?
 
GT Brock,

This is a great question. The C/I extension of Z21.21 is intended to cover commercial and industrial shut-off valves. The problem with a safety shut-off valve for a turbine is that it may operate infrequently, may have to close very quickly, and operate at potentially much higher pressures than the operating conditions detailed in the standard. In terms of meeting the 100,000 cycle life requirement, reason would dictate that results obtained for valves tested at 60 psi or less and/or at closing speeds much slower than may be required for turbine fuel shut-off, would not accurately represent performance of a high pressure/high speed valve required for turbine fuel shut-off.

B Carroll
 
Top