Gate Valve
Gate Valve
(OP)
I am asking for wedge material in the gate valves as stated in the API 600 trim 8 the wedge material shall be 13%Cr the manufacturer has deviated to ASTM A216 WCB +13%Cr, Is this acceptable and compatible with the seat material (ASTM A105+ Stellite)?
RE: Gate Valve
The wedge material of Trim 8 should usually come with Stellite to avoid galling between the seats and wedge.
The term "WCB + 13%Cr" usually means WCB carbon steel with 13%Cr overlay, which is not common unless the service is corrosive and the size of the wedge gate valve is huge.
The recommended pairing should be:
Wedge Material: A216 WCB + Stellite
Seat Material: A105 + Stellite
RE: Gate Valve
Wedge material: A216 WCB + 13Cr
Seat material: A105 + Stellite 6
Of course, you can specify the wedge material to be solid A217 CA15 (casting material equivalent to 13Cr), then again the price is much higher.
James Chan
RE: Gate Valve
Please realize that:
According to API 600, the seating surface (hard faced coating) material for wedge and seat shall be 13Cr or Co-Cr alloy.
The standard does not say the wedge/seat ring material shall be 13 Cr.
Regards
TZL
RE: Gate Valve
One of the surfaces (seat or wedge in case of a gate) needs to be hard and there needs to be aminimum and a difference. Don't think there is a requirement how the hardness should be made.
RE: Gate Valve
Gave the right answer IMHO
luis
RE: Gate Valve
RE: Gate Valve
I say this because when's the last time you've seen an A217 CA15 PT rating?
Luke | Valve Hax | https://valvehax.com/
RE: Gate Valve
Nominal Trim
410 - Hard faced
Trim code
F6HFS
Stem and other trim parts
410 (13Cr) (200-275 HBN)
Disc/wedge
410 (13Cr) (250 HBN min)
Seat surface 410+St Gr6 (CoCr Alloy) (350 HBN min)
Trim Material Grade
13Cr-0.75Ni-1Mn/1/2Co-Cr-A
Service
Universal trim for general service requiring long service life up to 593°C. As trim 5 for moderate pressure and more corrosive service. Steam, gas and general service to 540°C. Standard trim for gate valves.
I cannot tell a lie, I lifted this sometime ago. Shamelessly submitted without attribution.
RE: Gate Valve
Bruce | https://www.ntgdvalve.com