Tuesday 18 June 2013

API-rated instrumentation valves deliver system-level gains for wellhead OEMs

Wellhead equipment suppliers and operators can make major enhancements to their 'Christmas tree' and related equipment designs by using a new range of API-rated integrated valve assemblies from the Instrumentation Products Division of Parker Hannifin - the global leader in motion and control technologies.

The integration offered by Parker's new valve assemblies reduces weight by as much as 40% compared with double-block-and-bleed configurations using discrete valves, and can reduce space envelopes even further - by as much as 75%. Users can choose from a range of connection styles including flanged, welded, Grayloc hubs and Autoclave cone-and-thread connectors - to suit the particular installation.

The new product range provides integrated process-to-instrument interfacing solutions that dramatically reduce weight and size, and eliminate many potential leak paths and risk, compared with configurations based on discrete valves and connectors - the typical implementation approach used up to now.

Based on the design of one of the leading process to instrument valve manufacturers, Parker's Pro-Bloc range of integrated manifolds for interfacing instrumentation to process piping, the new Pro-Bloc API range integrates a complete double-block-and-bleed assembly of fire safe isolation and venting valves that is suitable for interfacing process pressure and temperature instruments. The assembly is available in three main forms: with ball valves, needle valves, or high-performance needle valves that can also meet the Class A or Class B ultra-low-emissions levels of the ISO 15848 standard. The new valve assemblies are initially available in three choices of pressure ratings: 5K, 10K and 15K PSI, and have all been independently tested for conformance with the API 6A specification for wellhead and Christmas tree equipment.

Up to now, OEMs and operators producing Christmas tree configurations and wellhead control systems have typically constructed any instrumentation interfacing subsystems required using larger process-sized valves that are rated to the API specifications preferred in this application sector. These systems have not benefited from the substantial size and weight savings - and designed-for-purpose flow paths - that are typical of the double-block-and-bleed manifolds that are readily available for instrument interfacing in other parts of the process world.

The integrated design also eliminates numerous interconnection joints, each of which is a potential leak path and source of unreliability, and system building cost; this can amount to a reduction of as many as four potential leak points compared to a system built from discrete valves.

The close-coupled flow paths inside Parker's Pro-Bloc API process-to-instrument valve assemblies provide another significant advantage, as they are ‘purpose-designed’ to support accuracy of measurement. In the case of the ball valve variant of the design, the flow path is completely straight, with a uniform bore. It is not possible to create such a short flow path with a system based on discrete valves, and it can also be very difficult to avoid bends - and sometimes changes of bore sizes - that impact measurement accuracy by generating turbulence. Parker has already had feedback from end users that its close-coupled designs are helping to support novel measurements that are being made on wells for asset integrity investigations.

Parker developed these new integrated process-to-instrument interfacing solutions rated to API 6A after application-specific project experience on wellhead applications, and is now making the technology available to the wider market.

"The API valve assemblies will cut the weight and size of the instrument-interfacing parts of their equipment to a small fraction of many current implementations," says Spencer Nicholson, Business Development Manager of Parker Hannifin's Instrumentation Products Division, Europe. "The highly integrated nature of the designs also provides near-perfect flow paths - with many fewer potential leakage points - a considerable reliability advantage for the harsh and remote operating environments in which many of these systems will be installed.”

The new integrated valves have been tested for conformance to API 6A specifications by an independent test house, as well as by the internal test laboratory that Parker operates at its European design and manufacturing facility in Britain.

No comments:

Post a Comment