GATE VALVE WITH SOLID 13 CHROME WEDGE AND SEAT RINGS 1

[hasanmoulana]

Dear Friends,

I have the below specification from my client. The spec mentions VALVE TO HAVE SOLID 13 CHROME WEDGE AND SEAT RINGS,BODY WEDGE GUIDES TO BE STELLITED. I do not understand why solid 13 chrome wedge & seat rings are required. My client also does not have an idea about this. Can any one assist me. Solid 13 chrome is too expensive. Further, also please assist me about BODY WEDGE GUIDES TO BE STELLITED. What is this.


VALVE, GATE, ANSI CLASS 150, FLANGED RAISED FACE,
BOLTED BONNET, OUTSIDE SCREW & YOKE,
RENEWABLE SEAT RING, BODY & BONNET: CARBON STEEL,
CASTING, A-216 WCB
END TO END DIMENSIONS TO ANSI B-16.10.
PACKING: JOHNCRANE 287-I OR EQUIVALENT.
TRIM: API NO. 8, WEDGE: SOLID (PLAIN)
SIZE IN INCHES: 6
STANDARD: API-600
BONNET BOLTS/NUTS: SA-193 B7/SA 194 GR.2H

VALVE TO HAVE SOLID 13 CHROME WEDGE AND SEAT RINGS,
BODY WEDGE GUIDES TO BE STELLITED.

 

[Kandeel76]

Hi,

This is classical specs,you can check manufacturers VELAN or KITZ which still manufacturing some gates wedges through this specs.

For SOLID 13 CHROME WEDGE AND SEAT RINGS, It was known as more tightness welded-in stellite 6 faced seats and flexible wedge in Cr13.
for STELLITED that means a very hard alloy of cobalt and chromium with cobalt as the principal ingredient and for surfaces subject to heavy wear.

Regards,
Kandeel

 

[reverman]

I think this is a bad interpretation of the spec. I believe they want a gate valve with a solid wedge and a 13% Cr seating surface. This could mean a solid 13%cr wedge but also a solid WCB wedge with a 13%Cr facing should work also.

Disclosure I work for Powell valve and on our class 150 gate valves in the 2 through 6" size we do use a solid A217 CA15 wedge (13%Cr)

For the most part this is a pretty standard stock class 150 gate valve spec. The big exception is the stellite guides. Adding stellite to the guides will add significant cost.

Honestly on a class 150 valve full stellite guides seems to be a bit of overkill. I can see justifying the cost on higher pressure valves but not on class 150