With nearly 20 years involvement in the various aspects of valve fugitive emissions it has been most interesting to see the evolvement of test houses. Some of my experiences and observations are shared below.

In-house
In 2008 the opportunity for end users to undertake fugitive emission testing in house is very limited. With the business models pressuring end users to out source, one of the first casualties is often in-house testing facility.

All of BP’s testing was executed at Sunbury, UK. BP was fortunate to have suitable testing facilities, which were called “concrete bunkers”, which permitted testing with methane at temperature. Full safety procedures were in place. The testing ran non-stop, often 24*7. The lessons learn were enormous. The knowledge gained led BP in a specific technical and commercial direction.

Fact; An important result from the original BP 1993 test was that only one packing was found to be acceptable. All others were poor by comparison.

BP closed and demolished the test house in 2000.

External testing house
I suggest that the end user should search for an external testing house that allows testing with methane. ChevronTexaco have been successful in their pursuit and have used Yarmouth Research and Technology testing facility in the USA. I offer my congratulations to David Reeve’s and his team.

Fact; An important result from ChevronTexaco’s 2003 test was that only one valve manufacturer managed to pass. By 2008 several valve manufacturers have been successful.

By suggesting methane as the best test medium does create a knee jerk counteraction in the market about safety, permits and meeting legislation. These are indeed valid but when managed correctly methane is perfectly safe. Some end users wish to use methane, as this is compatible with site measurements.

So its congratulations to James Walker for their test house use of methane. They have undertaken numerous packing tests. Other sealing companies use helium (?). *

There are those in the industry that prefer and support the use of helium as the test gas. CETIM in France and BHRG in the UK are such test facilities. It is believed that TOTAL has had valves tested at CETIM.

Valve manufacturers test facilities
All the valve manufacturers use helium as a test gas. * They are all unmoveable on the request to change to methane. Existing manufacturer plants would need significant investment to permit the use of methane. No end user has offered to pay for such an investment.

Where the end user wishes to utilise the valve manufacturers test facilities then they have no option but accept helium. Shell has strategically selected this route, which requires such tests for compliance with their company specifications. Shell’s impact on the market has been considerate. Cees Glansdorp’s and Tony Smart’s drive for a better environment is to be applauded.

Fact; An important result from Shell’s Fugitive Emission Type Approval tests is that many valve manufacturers have passed Shell’s tightness class Ahs and Bh emission limits.

Testing sponsorship
End users do appear to set up a testing strategy that requires the test costs to be the responsibility of the valve manufacturer. In an attempt to minimise costs the valve manufacturers have lobbied the industry for many years in an attempt to standardise the tests. Such lobbying has been in vein.

The reward for the successful valve manufacturers is that their valves could be used on the end user facilities subject of course to the normal technical and commercial assessments.

Brain Teaser? Why did BP’s tests in 1993 have only one supplier pass and yet 10 years later why was it that only one valve manufacturer was able to pass the ChevronTexaco’s test????

In many ways the BP and ChevronTexaco’s test procedures were “similar”. For example

• selection of the test valve selected from stock,
• the use of methane as a test gas,
• test pressure and temperatures reflecting typical operating conditions,
• thermal cycles 5 to 10.
• measurement in ppm following EPA 21 method using an OVA Foxboro 128 instrument.

* Please advise if this assumption is incorrect.

I have received many comments to date from previous fugitive emission articles. I thank you. These will be responded to in future issues of the magazine. Please indicate whether you wish to remain an ominous in the script or if you do not wish them to be used at all? So please keep-sending your comments.

Barrie Kirkman , Bsc CEng MIMech
barriekirkman@ntlworld.com
July 2008 Valve Wolrd article