Understanding end user valve approvals - Part 11d - Castings

Understanding end user valve approvals. Part 11d - Castings

Barrie Kirkman - 17 December 2015

Previous articles tackled castings as seen at the valve manufacturer by the end user. However the end user may also visit / audit a foundry. Now this opens up a total “new intriguing world”…….

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Mr Barrie Kirkman
Barrie Kirkman, BSc CEng MIMechE, writes a regular column for Valve World, bringing his own personal views from inside the valve business.
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Valve manufacturer & foundries

Typical supply set up is as follows;

  • The valve manufacturer uses only third party foundries (i.e. the most common)
  • The valve manufacturer has a “Joint Venture Foundry”.
  • The valve manufacturer is vertically integrated with their own foundry and also use other third party foundries.
  • The valve manufacturer is vertically integrated with their own foundry and use no other foundries.

 

1. The valve manufacturer uses only third party foundries (i.e. the most common)

Grinding off valve brand

My last comment on this option before moving onto the other models is to end users to be cautious and to fully understand why the valve manufacturer wishes to show you specific foundries rather than others. I have been involved with several clients and it’s amazing how often the same “foundries” turn up in the audits. The foundry personnel look at me, smile and the audit continues.

The end user should clearly understand the valve manufacturers casting volume and materials spread prior to visiting the foundry. Whilst at the valve manufacturer it would be of benefit to make a note of the foundry identifications on the castings. Ask and gain as much information as you can. This will give an idea of volume spread amongst their foundries. Is the end user going to accept all the foundries used or select a few?

Also question who designs the patterns. Are they supplied by the valve manufacture or developed at the foundry? Are they based upon “best practice, computer simulation or badge practice?” Do you understand what badge practice is? You may be “blinded” by riser and down comer design and methods to achieve good even spread of the molten metal and efficient cool down but not to worry, act informed. Evidence within the foundry should confirm the number of patterns for a particular valve brand. The end user should ask to see the pattern storage area. Is this well maintained and orderly? Or is the area a “junk pile” with no order? This applies to both investment and sand castings. The casting production hopefully will show some of the valve manufacturer’s brand in production. If not, why not?

The end user will need to make a judgment call. Normally the foundry visited will, in the eyes of the valve manufacturer, be the best as they want approval to use them. So let’s assume the foundry is acceptable but do they only accept this foundry or believe this is representative of other foundries used and accept all foundries presented? Some only accept the foundry visited.

Others qualify a short list of foundries after further audits whilst others accept all the foundries. It really depends on volume, manufacturing flexibility, costs and end user view on criticality of castings.

Note; Foundry identifications on castings are not always clear to understand.

  • A foundry may have their own specific identification.
  • The valve manufacturer can agree with the foundry an identification that is unique to the manufacturer / foundry. This is fully traceable with certification.
  • A valve manufacturer can also give a specific casting identification that is unique to the valve manufacturer but is used at many different foundries so traceability is not possible. Ah, you may say, but the original material certification will show the foundry name. True but often the data is transferred to another certificate.
  • There is another practice that, if seen by an end user, should immediately prevent valve manufacturer approval; the grinding off of the original valve brand / casting identification and the welding of new information on the valve. In this instance some companies specifically have a goods-in check point that the brand / casting identification is indeed the original cast and not welded.

 

2. The valve manufacturer has a “Joint Venture Foundry”.

Pattern Shop

Usually the Joint Venture foundry model is for a specific reason such as to be able to control the castings to an acceptable level for a valve manufacturer. One of the joint ventures partners is often a valve manufacturer that requires casting expertise through the other joint venture partner. This works very well. I have seen such JV’s that have been significantly influenced by the valve partner and complemented by the foundry partner.

Here you tend to see good western controls and practices which are more acceptable to end users during their visits. To some end users “the casting process” is an “unknown process” with little knowledge of what makes a good casting so by providing a familiar working environment does assist their assessment. Often visitors are restricted to ensure confidentiality is maintained.

There are other JV’s where, to be honest, the foundry partner has pulled the valve manufacturer quality low and end users find it difficult to see the added value of such a partnership other than it may be cost driven. The number of JV foundries is limited.

3. The valve manufacturer is vertically integrated with their own foundry and also use other third party foundries.

Casting identification

Vertically integrated valve manufacturing is always a preferred option to end users as this gives extra confidence in controlling all aspects of the manufacturing process. This has been proven time and time again. Also having one foundry only producing one valve brand is considered a “big plus” withseveral end users.

Normally the best foundry is the vertically integrated foundry. As mentioned above care should be taken on the likely volume of castings for this foundry versus quality of other foundries the valve manufacture uses. The true source should be investigated again using the casting identification and original material certification.

4. The valve manufacturer is vertically integrated with their own foundry and use no other foundries.

As stated vertically integrated valve manufacturing is always a preferred option but there may well be restrictions due to volume, special sizes and / or materials.

These manufacturers are often in the “niche” market?

In the next article I will move into much more detail when visiting a foundry suggesting typical areas that end users should be aware of.

Thank you for your continued support. Please contact me if you have any questions or different views. They are most welcome.

Barrie Kirkman, BSc CEng MIMechE, writes a regular column for Valve World, bringing his own personal views from inside the valve business.

Barrie can be reached on: barriekirkman@ntlworld.com.


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