Diaphragms Seal Services

Our latest product that we now offer for multi-instrument assemblies is our proprietary Low Volume Instrument Manifold (LVIM). These were developed to replace the old “Goal Post” configuration. They are great for instrument configurations where both instruments have displays that require the instrument to be in an upright position.

These are machined from solid bar or hex stock 316L stainless steel, and have 0.156” bores, which cut down on the overall volume of fluid in the assembly and relives some temperature effect error due to volumetric expansion of the fill fluid. They are offered in both 1/4″ NPT and 1/2″ NPT connection sizes.

We can provide pre-fabricated piping assemblies, which can be shipped assembled or separately from the diaphragm seal assembly. This cuts down on installation time in the field and many times in Waste Water and Water Treatment specifications we find that there are requirements for the units to come pre-assembled with piping. Piping is available in many different configurations both for flushing ports and off the process connection of the diaphragm seal), connection sizes and shut off valve specifications. Next time you come across a drawing or specification that calls for a “piping tree” you know who to call.

Excessive exposure to heat can cause your pressure gauges and pressure transmitters to read inaccurately. Most Bourdon tube pressure gauges will exhibit an additional 0.4% error in span for every 18°F above reference conditions (68°F). For example, if your instrument is running at a temperature of 200°F that’s an additional 3% error in reading added to the manufacturer’s stated accuracy. Keep your instruments accurate on critical applications by using diaphragm seals and properly selected additional heat dissipating elements.

We offer both the  Wika 4″ finned cooling element (Rated to 500°F) and the 8″ perforated cooling element (Rated to 750°F)  in both 1/4″ NPT and 1/2″ NPT, or can provide them welded to the diaphragm seal upper housing for particularly aggressive and critical applications, where fugitive emissions may be a concern.

Capillary assemblies are a great way to remote mount and instrument, measure level in a DP application, and can also protect and instrument from heat. There are many variables that need to be considered when selecting a capillary assembly. Aside from the standard “length, connection sizes, and material of the capillary”, there are factors such as, capillary internal diameter, proper fill fluid selection, calibration offset for positive or negative head pressure, and many more. Let us do the heavy lifting. If you can get us some simple details about the process, we’ll take care of the rest.

All of the above categories are really just “accessories” for diaphragm seals. They are basically, enhancements or upgrades, that are designed to solve a problem and protect you valuable instrument, and above all, ensure that instrument is reading accurately.

Detailed in the tabs above you found several options to accessorize. Some other accessories you may consider would be:

Snubber – A simple porous disc snubber or piston snubber is a great way to protect you instrument from pulsation and get more stable readings.

Pressure Limiting Valve (PLV) – is a device that is designed as a self-operating pressure shut off valve. It can be set at a specific pressure where it will shut off the pressure to the instrument and protect it from over pressure damage. These work very well when paired with a snubber, as it give the PLV more time to respond to a sudden pressure spike.

Lockwire – is simply a piece of wire that is attached to the instrument and diaphragm seal that is designed to deter an operator in the field, from removing or turning the instrument, compromising the fill of the sealed system.

Flushing Ring – is designed to be used in conjunction with a fanged diaphragm seal. It is basically a wafer style ring that fits between a specific sized flange. It sits under the diaphragm seal and can be machined with one or more flushing or test ports. These would typically be used for viscous process media or where particulates may be present and periodic back flushing is required. Another application would be to use the flush ring as an access point for the use external calibration.

Pictured above in an example of a typical submittal package that we provide at Colonial Instruments when requested. We make the submittal cover out with your pertinent company information, including name, phone, and email. With diaphragm seal assemblies we include a “shop sketch”, which is identified by a sketch number, which is also referenced, on the cover section, by line item. If there are multiple sketches for a project you and your client can easily reference the various drawings associated with each item.