Swagelok's Fast Loop Modules Give Analyzers a Big Boost

PrESS FLM could be the solution to your analyzer problems

A long distance between a sample tap and an analyzer shelter can make it difficult to obtain a useful analytical measurement. Ideally, the flow from the tap to the shelter should take a minute or less. But transport lines often are more than 30 metres and require high purge volumes to ensure that a fresh sample reaches the analyzer.

That's where a fast loop module, also called a bypass loop, can be a great addition to a system. Fast loop modules are designed to handle high flows in sample transport lines to reduce time delays for online analyzer systems. Located at the analyzer shelter and offering a bypass, the Swagelok fast loop module can isolate the sample system and introduce a purge gas for system cleaning.

Edmonton Valve & Fitting offers these modules as pre-engineered subsystems. Because Swagelok has worked out the design already, the fast loop module can be available with a single ordering number in weeks, not months. It offers a lot of advantages over trying to put something together on your own from available parts. 

"You'll find the functionality is improved from what people have done in the past," says Jim Smart, one of our account managers. "Then there are some safety features. With the interlocking handle design, users can be confident about opening them in the right sequence."

The Swagelok design includes two ball valves that switch flow to a bypass to isolate the sample system and analyzer during maintenance. These bypass valves maintain flow through the fast loop to keep the sample fresh at the bypass point. The interlocking handles allow for simultaneous actuation of the valves, while allowing for packing adjustments within an individual valve body. In some configurations, the drain and purge valves are locked into the bypass valves to eliminate the possibility of opening the drain or purge lines while the system is in sample mode. All handles can be locked into position to eliminate the possibility of accidental actuation.

Multiple configurations

The base model, described in Swagelok's application guide, download here, allows the fast loop to be bypassed when the analyzer is not in use. From there, Swagelok can create several configurations: with a return from the analyzer to the process line, with a return from the analyzer to a drain, or with a gas or liquid purge and manual drain.

An optional grab sample outlet and a relief outlet are available with all FLM configurations. All configurations also are designed to enable easy access to any component without disturbing other components in the system. Swagelok uses welded assemblies to reduce potential leak points and zero clearance fittings in straight run tubing sections.

No water hammer

Closing a valve in a high-flow liquid line causes extreme pressure spikes, referred to as water hammer, which can damage system components. Our fast loop module eliminates the possibility of water hammer by making full shutoff impossible. The bypass valves actuate simultaneously to eliminate the possibility of actuating only one of the valves. The three-way valve design allows flow to switch gradually from sample mode to bypass mode, instead of temporarily shutting off during actuation.

You can get fast loop modules in the 1/4 in. size, used mainly for gas samples, or the 1/2 in. size, which is usually best for liquid samples.

There's no need to re-invent the wheel, or the fast loop module. Swagelok has done the work. Let Edmonton Valve & Fitting show you how to reap the benefits, contact us today!