Trim 8 & Trim 5 1

[hasanmoulana]

my client requires gate valve with trim 8 with back seat bushing stellited for hydrogen rich service, but my manufacturer has supplied gate valve with trim 5. My manufacturer informs that trim 5 is superior to trim 8 & stelliting back seat bushing is part of trim 5. Can any one give me an idea how to handle this.

 

[hsbcn]

Trim 5 is indeed considered superior to Trim 8 as the disc is also stellited, not only the seat. But really, if your specs call for Trim 8 and you've ordered it, use Trim 8. Specs are there for a purpose.

Here's an overview of API trims:

http://alloyvalves.blog.com/alloy-valves/api-trims/

My focus: Alloy Valves Duplex Valves Monel Valves Inconel Valves [link titanium-valves.com]Titanium Valves[/url] Hastelloy Valves

 

[SNORGY]

hsbcn:

Thanks for the valuable summary of information.

On their website, I assume it's just a column / space thing where it references "Hard 41", and that what they really mean is "Hard 410".

Regards,

SNORGY.

 

[hsbcn]

hi SNORGY, yes Hard 410 (hardfaced 410) sounds right, rather than just 41. happy this was useful, and happy holidays!

My focus: Alloy Valves Duplex Valves Monel Valves Inconel Valves [link titanium-valves.com]Titanium Valves[/url] Hastelloy Valves

 

[reverman]

API 602 allows trim 5 to substitute trim 8 without notice. Not sure it it's an API 602 valve but that could help.

I will say I don't think I ever had a customer complain about getting upgraded to trim 5 from trim 8 once it's explained to them

It's still bad form they should let you know it's happening before shipping the valve.

 

[hasanmoulana]

Dear reverman,

Many thanks for your valuable suggestion. This is gate valve as per API600. Below is the alternate trim numbers mentioned in API-600 & my client is rejecting based on the below list. I need to convince my client to accept the valve. Could you please give me any other technical point to convince my client.

Specified Trim Number Alternative Trim Number

1 -----------------------8 or 8A
2 -----------------------10
5A ----------------------5
8A ----------------------8
10 ----------------------12 or 16
13 ----------------------14
12 ----------------------16

 

[hasanmoulana]

Dear All,

Many thanks for your valuable suggestion. This is gate valve as per API600. Below is the alternate trim numbers mentioned in API-600 & my client is rejecting based on the below list. I need to convince my client to accept the valve. Could you please give me any other technical point to convince my client.

Specified Trim Number Alternative Trim Number

1 -----------------------8 or 8A
2 -----------------------10
5A ----------------------5
8A ----------------------8
10 ----------------------12 or 16
13 ----------------------14
12 ----------------------16

 

[EagerLearner]

Hi,

I heard of trim a lot but what exactly is a trim. I tried GOOGLING but dont seem to get a satisfactory answer. In fact nothing. Is there a picture of it or something? In orifice fittings, often times it is stated either standard "A" trim, NACE trim standard or AASG trim. I cant find anything on this through search.

 

[vpl]

I tried a google search on "what is valve trim."

Here's a couple links that explain it fairly well:

http://nuclearpowertraining.tpub.com/h1018v2/css/h1018v2_23.htm

This is from wikipedia (

http://en.wikipedia.org/wiki/Valve#Trim)

Trim: The internal elements of a valve are collectively referred to as a valve's trim. According to API Standards 600, "Steel Gate Valve-Flanged and Butt-welding Ends, Bolted Bonnets", the trim consists of stem, seating surface in the body, gate seating surface, bushing or a deposited weld for the backseat and stem hole guide, and small internal parts that normally contact the service fluid, excluding the pin that is used to make a stem-to-gate connection (this pin shall be made of an austenitic stainless steel material).

I know the various trim #s refer to the material used. There are tables available as to which material goes with which trim.



Patricia Lougheed

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