Fugitive emissions, ppm, consent decrees and low-E packings: These are the words that make up a lexicon unknown in the valve repair world 25 years ago. This new vocabulary is one that anyone who deals with valves needs to learn so that the industry is prepared for what’s to come.
Regular readers of VALVE Magazine are already familiar with fugitive emissions (FE) control issues in the valve industry. What they may not realize is that the companies that service and repair valves are also now in the fugitive emissions abatement business. Any company that handles volatile organic compounds (VOCs), greenhouse gases or other nasty substances frowned upon by the Environmental Protection Agency (EPA) when released into the atmosphere must deal with these issues.
Many new valves are now required to have their fugitive emissions containment integrity verified by American Petroleum Institute (API) or International Organization for Standardization (ISO) standards. When EPA consent decrees are involved, a five-year, no-leak guarantee is often required by the government.
Repair companies also are facing these issues. Any repaired valves in FE service will have to be repacked with low-emission (low-E) packing as part of the repair process.
WHAT MUST BE DONE
The first step service and repair companies should be taking is to check with end-user customers to see if they have approved vendors for low-E packing. If not, those repair companies should confirm that their own packing vendors can provide them packing that has passed the API 622 graphite packing test procedure. Most reputable packing manufacturers have done this and have the certificates to prove it.
If a company follows the API RP 621 valve repair procedure, it also is in a great position to leverage the extensive documentation requirements of that recommended practice into a vehicle for quality assurance verification, which could make the company a valuable partner for a user. In RP 621, there are requirements for individual measurements on key fugitive emissions containment components such as the stem finish, stem straightness, stem run-out, and stuffing box finish and dimensions. The most important thing is all this key data must be provided on every valve repaired.
This means customers will have a detailed package of dimensional data (all key to better fugitive emissions containment) for each repaired valve in the plant. A good salesman for the repair company should be able to use this information to bolster the ability to offer a better total cost of ownership for a client’s repaired valve inventory. For the repair company, this could equate to repairing more “commodity” type valves that are currently uneconomical to repair because the cost of new valves is so low.
Low-E packing installation is similar to standard packing except for certain details, and the devil is in those details. The packing manufacturer’s installation instructions must be followed to the letter, because that manufacturer, as well as the repair company, may be on the hook for the five-year, no-leak warranty.
One of the biggest differences in low-E packing from standard packing installation is the amount of torque required to properly seal the packing area and limit leakage to less than 100 parts per million (ppm). The days of tightening packing gland bolts with a combination wrench are gone. Repair and service companies now have to use a calibrated torque wrench and load the packing to an exact recommended torque. Also, hardened-steel flat washers are required under the packing gland nuts. After torqing the packing, a metal tag with the packing type, date of repacking and recommended packing torque must be attached to the gland.
Although the learning curve for low-E repacking is not steep, future standards revisions may make it costlier and potentially more complicated. Right now, the RP621 valve repair document is undergoing its standard every-five-years revision in API. Fugitive emissions issues have placed a stamp in many paragraphs of the new document, even though it is still under revision.
If approved as it now reads, the revised recommended practice will require a repair shop not only to adhere to additional dimensions and tolerances on key components such as stem, stuffing box and packing gland, but also perform a production test following packing installation. This is to help verify that the repaired valve can achieve low-E performance. As drafted today, the required test will be a low-pressure (100 psi) methane test. The confirmation of leakage below 100 ppm will need to be verified via a VOC sniffing device. These machines are costly to purchase, but they can be rented by the week or month.
The proposed shell and packing production test requires the valve to be stroked three times and both the gasket and packing area to be sniffed. Since methane will burn rather fiercely, appropriate safety measures must be followed. This is not the kind of test that can be performed in proximity to any sparks or open flames. Methane does not play well with welding arcs or grinding sparks. As a result, a dedicated, segregated test area is the safest choice for testing.
ON TO NEW AREAS
The discussions surrounding fugitive emissions and packing thus far have centered on linear (multi-turn) valves, but API is now in the process of writing a quarter-turn valve-testing standard. This new standard would include various packing materials, including Teflon. After it is published, the key tenants of the document will undoubtedly be adopted by the end-user community and applied to repaired valves as well as new ones.
The Association of Wellhead Equipment Manufacturers is also developing a standard that will be applied to the upstream and midstream sectors of the oil and gas industry. EPA has recently targeted fugitive emissions from these valves, which have been ignored in the past.
The most important thing for the valve service shop management team to do right now is become educated, and there are many opportunities available for that. This June, for example, there will be a Valve World-sponsored fugitive emissions summit in Houston. Speakers will discuss virtually every aspect of the subject over a two-day period. An exhibition of fugitive emissions-related products and services will be part of the event. Also, the Valve Manufacturers Association, as part of its Valve Education program, offers fugitive emissions as part of the Basics Seminar curriculum. The next course is Oct. 18-20 in Houston.
Meanwhile, the API subcommittee on piping and valves will be discussing fugitive emissions standards as part of its agenda at the upcoming Spring Refining Meeting in Chicago in May. The API meeting (which costs to attend) is open to the public.
The subject of valve fugitive emissions control is only going to get bigger and bigger. The best defense against what’s to come is education. Valve service companies will be working alongside users and manufacturers to educate themselves on what needs to be done to play a meaningful role in helping to make the air we all breathe as clean as possible.