Process Connections

As someone once put it “the devil is in the details” and process connections, terminations, weatherproofing, and supports are devilish details in analyzer applications.  Designed and installed properly, these parts can ensure sample accuracy.  Ignored and these details can cost big money as well as pose safety and non compliance hazards.

Connection details differ as widely as the engineers who design them. In their simplest form they are commonly similar whether the sample is a gas or a liquid. Two typical details are shown below. 

In the simplest instance you will have some connection to the process. This might be a flanged spool or a weld-o-let in the line. You will have a sample probe and a shut-off or isolation valve so that the probe can be inserted and removed without shutting down the process. If the tubing between the sample point and the analyzer must be heat traced and insulated then the connection and isolation valve must be traced and insulated as well. Depending upon your ambient conditions a gap as small a 1/4" can create a failure condition.

"In many cases wet insulation is worse than no insulation because it gives a false sense of security."

There are many cases where it is advisable to precondition the sample before transporting it. The most common preconditioning done at the tap is to adjust the pressure. For a gas sample this is done to reduce the lag time of transport while liquid samples are sometimes vaporized at the extraction point and transported as a gas.

Insulating and Heat Tracing the Sample Connection

Wet insulation is worse than no insulation and sample transport bundles need to be sealed completely and protected from the elements.  A variety of heat shrink boots, sealants and jacket patch kits are required for complete weatherproofing.

Heat shrink boots are available in a variety 
of sizes and configurations. 

Wet insulation containing water soluble chlorides can cause accelerated stress corrosion of stainless steel and result in process leaks.  

Correct selection and installation of power connections and terminations with correct electrical code approvals is another critical aspect of the sample transport system.  There are serious safety and performance issues with these details and O’Brien Analytical are The industry experts in both the design and installation of these critical components.