The main functions of diaphragm seals are to protect and separate pressure-sensing instruments from the process media (fluids), while permitting the sensing device to measure the media pressure. A diaphragm seal consists of a flexible membrane that is located between an upper and lower housing. Diaphragm seals can connect to the sensing devices directly or by using capillary lines. Many process applications such as sanitary, environmental can use these seals.

Diaphragm seal manufacturers can fabricate different types of diaphragm seals such as welded, clamped and capsule seals. Because complex factors can influence the accuracy/performance of a diaphragm seal and a pressure sensor assembly, manufacturers also offer a wide array of diaphragm seal designs to meet a variety of process requirements. Some important parameters to consider for the proper selection of these seals are diaphragm size and flexibility, temperature and pressure range, type of process media and its reaction with the seal materials.

Before buying from a diaphragm seal distributor, some options to consider are:

1. Find diaphragm seal suppliers that offer different types of seals.

2. Select custom diaphragm seals for unique applications.

3. Choose a diaphragm seal according to types of process media.

Action Steps
The best contacts and resources to help you get it done

Select diaphragm seal providers with a wide selection of products

When you require different types of seals (clamped, capsule, etc) or seals for different applications, it is important to find makers of diaphragm seals that have a wide selection of products to accommodate these needs. You should also look for a manufacturer that has good information about diaphragm seals to help you with product selections.

I recommend: Daughtridge Sales offers different brands of diaphragm seals like Ashcroft, Wika, U.S. Gauge and others. There are seals for different types of applications such as low pressure and corrosive. Blacoh Fluid Control is a diaphragm seal manufacturer that also carries many different types of products for various applications. These suppliers of diaphragm seals also provide good technical info.

Search for a diaphragm seal provider for complex application requirements

For challenging diaphragm seal design applications that require a special connection, certain materials or have unique configurations, a customized product is the best option. You should choose manufacturers with an experienced engineering and design staff that can handle complex design specifications.

I recommend: Ashcroft is a diaphragm seal provider that offers made-to-order seals to customer specification. This manufacturer has many different types of seal, services and provides good technical info about diaphragm seals such as a corrosion data guide. P I Components can also produce customized or special products for sanitary and other applications. This diaphragm seal supplier features one of the most complete lines of this product.

Get the right diaphragm seal for different process media applications

There are applications that need seals that must meet certain standards. For instance, some environmental applications may have to use welded seals that meet EPA standards. Likewise, sanitary application may require a hygienic connection to the process media that also has to meet other standards. Look for diaphragm seal distributors or manufacturers that carry an extensive inventory of products for diverse media applications.

I recommend: Ametek has different series of products for many process media (beverage, pharmaceuticals, etc.) and applications. There are products for sanitary, fugitive emissions and other applications suitable for different process media, which meet different standards. REOTEMP Instrument has a good selection of seals available in a variety of configurations for diverse applications. There are mini, sanitary and special seals.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  When selecting diaphragm seals, it is important to consider the diaphragm size. A larger diaphragm seal can provide a larger volumetric displacement.