Low-E Valves
Effects of consent decree compliance on certified low E valves and certified Low-‐E packing procurement and approvals
In old movies about the beginning of the petroleum industry, a well was drilled with hope and promise and just when everyone was about to give up, the ground would shake and a giant plume of black liquid would shoot into the air, covering the land, plants and drillers, who danced around whooping and hollerin’.
This might also be what was considered early leak detection. Things have tightened up since then.
Now, the Environmental Protection Agency (EPA) estimates that 60% of fugitive leaks come from valves, which makes them very interested in valve leak performance. A consent decree means that the plant did not meet the EPA’s standards for fugitive emissions and specifies the changes required to avoid a permanent shut down. This involves the implementation of a Leak Detection and Repair (LDAR) program for the plant.
While being under a consent decree mandate sounds drastic, consent decrees are common and allow a plant to keep operating while the required changes are made. About five years ago, 85% of US refiners tested were operating under a consent decree.
One of the primary parts of these consent decrees was the mandate that specific valves and packing should be certified Low-‐E.
The various consent decrees outlined the qualifications for a valve or packing to be certified Low-‐Emission or Low-‐Leaking:
“Certified Low-‐Leaking Valves” shall mean valves for which a manufacturer has issued either:
- a written guarantee that the valve will not leak above 100 ppm for five years; or
- a written guarantee, certification or equivalent documentation that the valve has been tested pursuant to generally-‐accepted good engineering practices and has been found to be leaking at no greater than 100
“Certified Low-‐Leaking Valve Packing Technology” shall mean valve packing technology for which a manufacturer has issued either:
- a written guarantee that the valve packing technology will not leak above 100 ppm for five years; or
- a written guarantee, certification or equivalent documentation that the valve packing technology has been tested pursuant to generally-‐accepted good engineering practices and has been found to be leaking at no greater than 100
The tests also require documentation, not just a warranty stating that the valve or packing meets those requirements.
The American Petroleum Institute (API) released testing protocols for manufacturers to follow and the valves and packing should meet these testing standards and procedures. The International Organization of Standards (ISO) also has testing guidelines, ISO test 15848-‐1, but the test media must be methane not the usual media, helium, and the test method must be EPA’s Method 21. The EPA requires methane as the testing media because they have determined that methane is the most destructive to the environment.
If the API protocols are followed, valves and packing tested should meet the applicable testing procedures of:
- API 622 -‐ Type Testing of Process Valve Packing for Fugitive The tests consist of mechanical and temperature cycles, while the tested packing is contained in a precision-‐machined test instrument.
- API 624 -‐ Type Testing of Rising Stem Valves Equipped with Graphite Packing for Fugitive Emissions (linear type.) It must be done with packing material that meets API
- API 641 -‐ Type Testing of Quarter-‐turn Valves for Fugitive Emissions. Also needs to meet API 622
It should be noted that the EPA has not implemented an overall definition of a Low-‐E valve or packing. It just specifies in the consent decrees the performance levels both must meet. This has allowed manufacturers to use different language in their own definitions which can lead to some confusion over what is designated Low-‐E valve and packing.
The effects of these consent decrees on procurement have been wide ranging.
Manufacturers had to decide whether they would produce valves and/or packing that could be certified Low-‐E. Most manufacturers have decided to produce Low-‐E valves and packing and some now make only Low-‐E products. For example, CPV products are now designed to meet or exceed fugitive emissions standards.
A purchaser needs to carefully check both the manufacturers and/or suppliers warranties and guarantees, but it is more important to review the actual data from the tests. That includes the test “small print” -‐ results from each part of the test to make sure no part failed. As for the warranty, it should include the statement that it is good for at least 5 years, not just that the valve and/or packing met the 100 ppm test.
While an LDAR refers to leak detection and repair, consent decrees have prompted companies to shift their focus to preventative maintenance. This proactive approach looks to implement a maintenance program that catches and prevents problems before they happen. This means the valves and packing don’t reach the point that they fail the consent decree requirements or, better yet, are kept in such good condition that a consent decree is avoided altogether.
One of the recommendations to insure the plant is in compliance is to replace all valves in a plant with Low-‐E valves to prevent mix-‐ups. Plants that have made the switch found that the cost differential is negligible when replacing non-‐Low-‐E valves with Low-‐E valves rather than non-‐Low-‐E valves.
Making sure all the valves required to be certified Low-‐E are in place and working properly takes cooperation and buy-‐in from all divisions of the plant, from management to maintenance. Proper training of employees is important and looking at the manufacturer or suppliers training programs should be part of the procurement process.
Record keeping has become even more important, from tracking and storing purchase orders to leak monitoring data. Software and tags have both been developed and continue being upgraded to facilitate these tasks. Some companies are now asking that the Low-‐E certification status be on the packing slip documents.
Consent decrees have also created opportunities for valve and packing manufacturers to share and cooperate in the development of their products like never before. Overall, they have made the industry re-‐evaluate its practices and standards. Leak detection has come a long way from its whooping and hollerin’origins.