Stellite vs. 316 SS in Low Temp., Sour Applications 1

[auzie5]

I have noticed that in many low temp. sour service check valves Stellite 6 is being offered as the disc material. The valve spec I'm working from specifies to use 316 SS for the disc.

I have two (2) questions:

1. If Stellite 6 is an overlay shouldn't the valve manufacturers specify what the underlying material is? (i.e. 13 Chrome would not be suited for low temp vs. 316 SS which would be acceptable).

2. Is Stellite 6 an acceptable substitute for 316 SS in low temp. sour service applications (i.e. acceptable but probably more expensive?).

Thanks in advance for any feedback. I've assumed that Stellite 6 is an overlay which requires a parent metal to start with.

 

[SJones]

See attached. Toughness requirements could be an issue as could suitable corrosion data for compliance with ISO 15156-3

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[reverman]

1. Yes you want to confirm what the underlay is. It should either match the body or be suitable stainless like 316. Getting a 410 would be bad.

2. This is really up to the end user but for the most part yes. Stellite will work fine in the most services and most customers will view it as an upgrade.

Stellite 6 is a weld overlay. You can get solid cast stellite that is equal to stellite 6 however I don't believe technically it's called "stellite 6". This is pretty rare though