Storage Life of Vent Valves

[Rafael Camara]

Hi colleagues,

We have some venting valves (Drukon GmbH) used in flexible pipes for oil production which uses PTFE and NBR in the sealing system (O-rings, x-rings, back-up rings and filter retainer). Our internal valve specification requests a service life of 20 years, but doesn't specify storage life.

I'm in doubt if I need to control the storage life of these materials separately or consider the complete valve assembly and specify a storage life for the complete assembly.
Which standard(s) should I be based for this consideration?

The supplier certificate doesn't specify anything about it, neither sealing system nor valve assembly.

Thanks in advance for your help!

Brgds,
Rafael Camara

 

[Danlap]

Hi Rafael,

It is really up to your judgement.
Assuming your storage facility is at ambient temperature by general definition (15-30 degC) and dust free, then standard plastic/pallet/boxes and general proper concept storage e.g. some parts not borne others weight, etc. should be sufficient.
Usually valve assembly storage is the one that is ready to use / plug and play once required for maintenance and shut-down. And spare parts of which stored on separated room usually used for common replacement e.g. gland packing and O-Ring after valves being used for xx hours replacement strategy.

For special attention:
- very clean application, then usually valve assembly is equipped with end cap to prevent potential dust entering the bore.
- Oxygen, Ethylene Oxide, Hydroflouric Acid, etc. shall be hermetically sealed for both valve assembly and its spare parts.

How old before thrown away?? Again it is up to you.
Two things that are usually considered by company and part of warehouse 'disposal' protocol:
- Depreciation (economic) value of the valves and spare parts. After reaching certain years, some parts become sum zero value. Thus have no economical advantage to be kept, and only eat spaces.
- Aging of material. It is like car tyre, even though not used the rule of thumb is after 5 to 7 years shall not be used/thrown away.
Some soft parts did aging test in a lab, but in order to find this (lifetime) out you have to trace back down to the manufacturer of those material or parts, and ask.

Combining both consideration, for bulk material, my company usually throw away valves and materials that have reach 10 years unused lifetime.
Some approach that we use now is keep it as non-stock. Meaning supplier keep the stock on behalf of us, so whenever required or there is 'newer' development yet similar design in the future, then we can have the right parts asap.

Regards,
MR

https://nosuchvalve.com

All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected

http://www.eng-tips.com/faqs.cfm?&rat1=2&fid=376

 

[Rafael Camara]

Hi Danlap,

Thank you very much! I'll ask the supplier about the ageing results and recommendation about this issue.

brgds,
Rafael Camara