Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Gate Valve

Gate Valve

Gate Valve

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

Hi Mostafa,

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

I don't agree with @wornandwound, Trim 8 should be a combination trim, the seating surface should be 13% on one side, and Hardfacing on the otherside. For gate valve NPS 2 and above, the most common selection is:
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

Hello, Mostafa,

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.



RE: Gate Valve

The standard say that the base material of the trim should be minimal equal to the body material, so A105 or WCB is accepted.
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


RE: Gate Valve

I agree with JchanMe as well. Wedge material is a fair bit higher if you use solid A217 CA15 for the valve

RE: Gate Valve

Just FYI. A217 CA15 is "acceptable" replacement for WCB with 13CR overlay. for smaller valves, this is much easier to manufacture.

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

API Trim Number 8
Nominal Trim
410 - Hard faced
Trim code
Stem and other trim parts
410 (13Cr) (200-275 HBN)
410 (13Cr) (250 HBN min)
Seat surface 410+St Gr6 (CoCr Alloy) (350 HBN min)
Trim Material Grade
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

The trim8 mean wedge sealing surface overlaying 13Cr, not the whole wedge 13Cr. Just like the seat ring stellite, not the whole seat stellite material.Moreover, casting material code of 13Cr is CA15.

Bruce | https://www.ntgdvalve.com

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close