Achieving a leak-free connection in offshore oil and gas environments is the Holy Grail for many piping and instrumentation engineers. But traditional hookups use a multitude of valves and fittings & creating lots of potential leak points.
The good news is, adopting ten easy steps can radically reduce leakage risks and achieve substantial cost and efficiency savings. Here are the first five steps to get you started.
Step one: use integral fittings
Using integral fittings is one of the quickest ways to cut the risk of galling. Integration negates the need for PTFE tape or sealant; valves are shorter, lighter and more compact, leading to smaller installation size; and this approach is less labour intensive – cutting the likelihood of sealant application errors, which can lead to drops in valves and cause contamination.
Best of all, valves with integral fittings are actually cheaper to buy. So using integrated valves from a reputable fittings manufacturer such as Parker can save you both time and money.
Step two: don't over-tighten manifold connections
Over-tightening manifolds can be a problem, particularly if NPT elbows are involved. Over time, this can cause component damage, reducing the life of the product.
With manifolds such as Parker’s PTFree connect™, connections are fitted into the body of the valve, with a metric parallel thread onto a stainless steel gasket. The fitting is then tightly torqued, pinned and leak-tested prior to sale. That means less likelihood of any damage to the manifold, as well as making it easier to align the impulse lines perfectly first time.
Step three: switch to integrated tube connections
When connecting pipe to tubing, one typical solution is to create a flange connector. Often this involves back welding to create a permanent joint. However, that also creates additional expenses in the shape of a welder and a welding permit; and as welding involves dissimilar materials, this also increases the risk of product corrosion.
By using products machined from one piece, there’s no need for the fitting to be put in, as it’s already integral to the design. That means no welding, no corrosion and quicker installation times.
Step four: reduce the number of valves
Traditional multi-valve hookups valves are especially prone to vibration and require support fabrication. Putting all the valves in one body (modular valves and Monoflanges) removes the need for additional support, is less vibration-susceptible and simultaneously reduces the number of leak paths. Added with quicker install times, there’s potential for substantial cost savings.
Step five: change to a Parker differential pressure transmitter
In fluid environments such as oil refineries, precise flow rates are critical. If a differential pressure transmitter (DP cell) doesn’t read correctly, the flow may display one result when the actual flow through the pipeline is completely different. That’s why transmitters are regularly taken to workshops for recalibration.
The downside of many conventional hookups is that they typically feature lots of bolts, making unhooking and rehooking the equipment time-consuming. But Parker differential pressure transmitters have a unique release mechanism key, which allows the engineer to remove the unit in less than a minute; and with no obstructions on either line, the possibility of gauge line error is reduced.
What’s more, by coupling directly to the process pipeline, there’s less need for NPT and tubing (thus removing potential leak points and galling risks).
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For further information and advice on achieving leak-free connections and overcoming operational challenges in technical environments, please visit Parker’s Instrumentation Products Division pages or find your local distributor.
Article contributed by Jim Breeze, product manager, Instrumentation Products Division Europe.