MSS-SP Valves Certification

[dynamics2004]

Hi All,
I am wondering if anybody can extend his help to me as I am procuring a small size valves up to 2.5" mainly bronze, brass and Ductile/Cast Iron in compliance with the relevant MSS, however, i am requested to ask the manufacturer to provide us with EN 10204 2.2 type of certificates for the following parts:
1. Body 2. Bonnet 3. Trim Components


The vendor / manufacturer has no matter for furnishing such for the body and bonnet while for the Trim components he isnt able and informing that this an API terminology and couldn't be applied onto MSS valves.


Really I am confused whether should I believe the vendor/manufacturer or no?

Thanking for your kind response

 

[dynamics2004]

to re-write the query is the Trim related to the API valves only?

please i am need of your kind help

 

[SJones]

EN standards are European and nothing to do with API. Similarly, in this instance, EN 10204 relates to inspection documents for materials and is nothing to do with MSS either; it is pure quality assurance. How will the valve supplier demonstrate the quality of the trim materials to you, the purchaser?

Steve Jones
Materials & Corrosion Engineer

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

All answers are personal opinions only and are in no way connected with any employer.

 

[bcd]

The root of your problem is that you are asking the producer of high volume commodity type products an order with special requirements, on products where it is impractical to do. Certification of materials requires each piece to have a unique serial number that permits you to trace its origins back to a test report. Try placing a unique number on DN15 trim components. Very tough. And then, how would you, the purchaser verify the unique number on parts inside the valve after it is assembled? Will you take it apart to do so? At some point, you need to trust the manufacturer. Any well known manufacturer that has been in business for many years wants to ship you a quality product that has no problems. If you buy the least expensive import from a fairly new company in a low-cost country, then you must ensure the product quality meets your expectations.

MSS standards are what manufacturers agree are commercially reasonable and practical for the types of products and the customers they normally do business with. If a requirement for type 2.2 certificates does not appear in the MSS standard, or in the material standards for the parts used to make the valve, then you are asking for something that is not normal business practice for many manufacturers.

 

[SJones]

2.2 is a certificate of compliance with 'typical results' - what's difficult about that commodities, or no commodities? It should be part of the manufacturer's quality system irrespective of the valve manufacturing specification.

Steve Jones
Materials & Corrosion Engineer

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

All answers are personal opinions only and are in no way connected with any employer.

 

[bcd]

Lets say you have multiple suppliers for a key part, like the ball or stem. Having more than one supplier is good safe business practice, and you need to give enough business to each to keep them as a supplier. The parts come in and they are all placed into a single storage spot. Without serial numbers, how would you know what part came from each supplier? When a majority of customers don't care about certification, why increase the factory costs trying to segregate materials by incomming lots? Also consider that purchase price is very critical in high volume parts, so the manufacturer allows as many material options as possible. The ball and stem could be cast or from bar stock, and of several possible grades of austenetic stainless steel. The suppliers are given a list of acceptable materials and they are free to chose what is most cost effective for them at the particular time the part is being made.

Considering multiple suppliers and multiple material options, how do you give a certificate with "typical results"? This is the reality in the comodity business.

 

[SJones]

Could it be by simply quoting typical results? The manufacturer simply has to state that the materials comply with the order and provide 'typical results'. How did the manufacturer pick the subcontractor in the first place? Possibly by examining some typical results that demonstrated that the specification could be met? From a quality point of view, the valve manufacture should know which subcontractors materials have gone where in case there are later issues. The manufacturer has been asked to supply 2.2 certificates, and the answer given is not correct, essentially, it smacks of 'we don't want to supply the requested inspection documents.' Of course, if the manufacturer does not have an ISO 9001 quality system, the discussion is moot anyway.

Steve Jones
Materials & Corrosion Engineer

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

All answers are personal opinions only and are in no way connected with any employer.

 

[dynamics2004]

thanks all for your input...actually, as advised above I contacted the manufacturer and i am still awaiting his feedback specifically for the point of how is going to assure the quality of the trim parts but the question which is raised if 3.1 certificate is offered for both the Body and Bonnet or Body and Cap doesn't this be considered a higher level than of assurance than 2.2 certification type?

Looking forward for your feedback

Best,

 

[SJones]

In theory, 3.1 should offer a more direct verification of quality, but that wasn't your question. So, you started with 2.2, and now you are thinking about 3.1. Have a good think because the cost of the valves will rise.

Steve Jones
Materials & Corrosion Engineer

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

All answers are personal opinions only and are in no way connected with any employer.

 

[dynamics2004]

THANK You all for your kind replies, we agreed on 3.1 certification type as it more advanced than 2.2 and provides more details but Unforunetly , the point which is still holding up is the Trim Components and their correlation to API 600 requirements as till of now no clear answer is received.

do you have any suggestion in this regard?

thanks,