WIKA USA has a long history of providing the process industry with innovative solutions. One of them is the AWS, our all-welded diaphragm seal gauge that eliminates potential leak points and other issues associated with loosened connections.

The process industry relies on diaphragm seals to protect sensitive pressure instruments, keep media uncontaminated, and make system monitoring more reliable. Yet some challenges remain:

  • Vibration and pulsation that loosen fasteners
  • Process media that corrode certain O-rings and gaskets
  • Extreme temperatures that cause threads to pull away from each other

Each of these process conditions results in a poor seal, which could mean inaccurate readings and fugitive emissions.    

Among WIKA’s many innovative solutions for the process industry is the AWS. Here is how our all-welded seal gauge solves these challenges.

Challenge #1: Vibration and pulsation cause fasteners to eventually loosen

Thermal cycling and many other process conditions produce vibration and pulsation, which means that clamping bolts and other fasteners sometimes work themselves loose.

Solution: A key feature of the All-Welded System is that the upper and lower housings of the diaphragm seal body are welded together. This eliminates the need for clamping and fasteners. The industrial process gaugeof this assembly is also permanently welded to the upper housing of the seal body, thereby eliminating leak paths.

Even under heavy vibration and pulsation, the AWS maintains its seal integrity, making it the perfect design in these types of challenging applications.

Challenge #2: Sealing materials incompatible with the process media

The O-rings and gaskets used in diaphragm seal bodies are often made of elastomers. However, elastomeric materials vary in their resistances against different process media.

Solution: WIKA’s all-welded process seal gauge has a recessed design, with the diaphragm welded to the upper housing. Our innovation eliminates the need for O-rings and gaskets, thus removing the issue of elastomer incompatibility. This makes the AWS ideal for use with corrosive, contaminated, or viscous media.

Challenge #3: Poor thread contact between the gauge and seal body

The diaphragm seal body attaches to the pressure gauge via a thread connection. This connection is usually tight, but in extreme temperatures, materials can expand or contract – and potentially release gases or system fill fluid into the environment.

Solution: The process gauge of an AWS is permanently welded to the upper housing of the diaphragm seal body. This eliminates the possibility of poor thread engagement.

An additional benefit of our diaphragm seal assembly is that it is fully contained and tamper resistant. This qualifies the AWS as a dual-containment system, making it a leader in safety and environmental responsibility.

The AWS: Two innovative products welded into one

To create the All-Welded System, we took two of our highest-performance instruments and expertly welded them together into one exceptionally reliable solution.

Models M932.D1, M933.D1

All-Weld System (AWS)

The 23X.34 XSEL® process gauge is expressly designed for demanding conditions in the process industry:

  • Stainless steel movement and socket to withstand corrosive environments
  • Fiberglass-reinforced thermoplastic (POCAN) case for excellent load-cycle stability and shock resistance
  • Pressure measurement from vacuum to 10,000 psi (690 bar) in combination with an AWS
  • Movement with a built-in 50% over-range protection with no loss of accuracy
  • A choice of liquid case filling for applications with high dynamic pressure loads and vibrations, and to protect gauges from environmental ingress
  • Standard equipped with a threaded restrictor to reduce the impact from pressure spikes and high dynamic pressure cycles
  • Fully traceable assembly with order and material information engraved on the gauge
  • Approval requirements and certificates (EU, Canada, CIS countries) upon request

The bottom half of the assembly is the model 990.34 diaphragm seal with welded design. It is made to withstand corrosive, hot, or viscous media, and has a measuring range between 15 psi and 10,000 psi (1 to 690 bar). The diaphragm, lower housing, and upper housing come standard in stainless steel, with the option for Monel or Hastelloy.

WIKA’s All-Welded System is the solution for many challenging applications in the process industry. Contact us for more information.

Products mentioned in this blog:
•  M93X.D1 All-Welded System (AWS) diaphragm seal assembly
•  23X.34 XSEL® process gauge
•  990.34 diaphragm seal with welded design


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