Large-bore double-block-and-bleed manifold

The new 25mm large-bore double-block-and-bleed manifold from Parker offers a flexible isolation function for process control, measurement and sampling applications

Parker Instrumentation has launched a 25mm version of its successful Pro-Bloc one-piece double-block-and-bleed manifold.

The current smaller bore versions of this product family are used extensively within the process industry, primarily for connecting remote monitoring instrumentation to process lines and pipework.

The new 25mm full-bore design significantly extends the application diversity, by providing a high flow rate capability unit that can form part of the processing system itself.

Typical application areas include offshore oil and gas platforms, refineries, and chemical and petrochemical plants.

Like all Parker Pro-Bloc double-block-and-bleed manifolds, the new 25mm version is machined from a single piece forging, eliminating many of the joints demanded by conventional designs based on discrete components.

This reduces the number of potential leak paths and results in a smaller, lower mass unit that imposes less loading and vibration stresses on the process line.

The overall effect is a substantial improvement in operational safety factors and reliability, with the added advantages of reduced installation time and cost.

"As with existing 10mm versions, the new 25mm Pro-Bloc allows engineers to specify a manifold solution that can substantially reduce weight and the number of potential leakage paths in a processing system", says Parker Instrumentation Market Development Manager Brian Rice.

"Compared with assemblies made from discrete components, this arrangement can boost the integrity and safety of the processing system, and reduce costs by eliminating labour".

25mm Pro-Bloc manifolds can handle 35 to 39 Cv flow rates and are particularly suitable for processes involving viscous media, or media with entrapped solids, where the large bore size helps maintain maximum flow.

The manifolds are also ideal for offshore applications, because they are less prone to the blocking effects of hydrate formation.

Further applications include media sampling, and storage vessel venting and draining - especially where sedimentation could block smaller bore products.

The 25mm manifolds are also suitable for use in vessel level detection systems.

Many of these work by measuring differential pressure, which is rarely very high, so a larger bore facilitates better measurement.

All Pro-Bloc manifolds feature flange interfacing to facilitate connection to the process piping, with a choice of single, double or triple flange configurations, and raised spiral or ring type flange faces, for application flexibility.

There is also a choice of two basic body styles: a flange-to-flange version for mounting in-line with process piping, and a version with a flange on one end and either a compression tube fitting or an NPT taper thread on the other, for connecting to instrumentation or further elements of the process.

The compression tube fitting option requires no thread sealant, and is therefore particularly suitable for applications where contamination risk must be eliminated.

As standard, the manifolds are fabricated from carbon steel, low temperature carbon steel, stainless steel or duplex, and depending on the chosen flange class, can meet ANSI class 2500 pressure ratings.

Each manifold is available with six different flow arrangements, and a choice of ball, OS and Y (outside screw and yoke) or needle valves for venting.

The primary and secondary isolation function is provided by the Parker new 25mm Hi-Pro ball valve.

This high-integrity design works on the floating ball principle, has dynamic response seats, an anti blow-out stem, and offers 100% bubble tight operation.

The valve seats are designed for inherent cavity relief, assuring complete venting downstream of any process medium trapped within the valve cavity.

PTFE seats are provided as standard, giving an operational temperature range of -54 to +204 degrees C, with PEEK seat material available as an option to extend the upper limit to +232 degrees C.

The valves are fitted with an industry standard colour-coded operating handle: blue for isolation valves, red for vent/bleed/drain/test.

Valves have a low actuation torque, even at high operating pressures, and employ the Parker patent-pending Tru-loc safety system to guard against accidental or unauthorised operation.

With this addition to the range, Parker now offers a wide choice of double-block-and-bleed manifold bore sizes, to suit in-line process control and stand-off process monitoring applications.

The Pro-Bloc family includes models with probes for process sampling or injection.

Further options include fabrication from exotic materials such as Super Duplex, Monel, 6Mo, Hastelloy and Incoloy 625, for applications in harsh operating environments, and/or involving corrosive media.

"Parker already offers all the basic instrumentation control and connection functions through its range of valves, manifolds and fittings", adds Brian Rice.

"This addition to the portfolio is extending our offering in the processing arena, allowing end users to procure a very wide range of products from a single world-class vendor".

Back to top