Unique Diaphragm Seal Solutions

At Bliss Anand America, we don’t like saying the word no. We know that we have experienced engineering and production teams, and armed with the right tools, we believe they can solve any problem.

So when BP came to us with a unique solution, we put our best people to the test. Working with our partners Badotherm, Bliss created a special solution to suit BP’s requirements.

The Application:

  • Very high process 
temperature – 760°F
  • Small process connection – 
no larger than 1”
  • Process fluid is a gas with high levels of hydrogen, and small amounts of H2S and NH3

The Concerns:

  • Are there any fill fluids that handle temperatures up to 760°F?
  • EJX430 (preferred Yokogawa gauge pressure transmitter) can only handle up to 248°F
  • Durability of gold coating – specifically regarding thermal shock at startup
  • Materials and NACE certification requirements

Bliss-Badotherm’s ApproachIMG_1625

  • Use BSO-48 as a fill fluid to handle temperatures ranging from -4 – 788°F
  • Use EJX530A transmitter rather than EJX430, as it contains fully welded construction (no gaskets or threads). It is highly recommended for high temperature/high pressure applications
  • Supply a 1 piece BF design with a thermal reducer
  • Supply gold-coated seal with 40μm on 316L diaphragm and other wetted parts. Alloy 400 specified by customer is only suitable for temperature below 392°F

Through perseverance, a lot of back and forth and discussion, and a creative mindset for solving problems, Bliss-Badotherm is now the only supplier (globally) for gold-coated seals with high temperature fill fluids.


For more information about our Gold-Coating, download our brochure here: Badotherm Diaphragm Seal Solution Gold Coating

For more information about our High Temperature Diaphragm Seals, download our brochure here: htds-seal-solutions


Bliss Anand-Badotherm Joint Venture

Bliss Anand is always striving to give you bigger and better, and in an effort to do this, a little over 16 years ago we partnered with Badotherm Netherlands, a manufacturer of diaphragm seals. Our joint venture allows both companies to expand their horizons beyond traditional offerings.

Wherever Bliss Anand goes, Badotherm comes too, with the latest expansion entering the US market in 2012. Our facility in La Porte, TX has a state-of-the-art filling station on our manufacturing floor where we manufacture, assemble and fill seals for 2-3 week delivery within the region. Other manufacturing facilities are located in Europe, Asia and the Middle East.


Through the Bliss-Badotherm partnership, we manufacture specialty seals to meet your most extreme requirements. With Zirconium Seals (for Urea/Ammonia Applications) High Temperature Diaphragm Seals (up to 1100°F), PTH Seals, Gold-Coated Seals (for Hydrogen Services) and Low Gauge Pressure Seals (as low as 5mbar), we are able to bring you a range of patented solutions designed to cater to your needs. Standard seal solutions are also available, often for purchase off the shelf.



As with everything we do, it isn’t just about the product up until the point of purchase. Both Bliss and Badotherm are family-owned companies, building partnerships based on transparency. You can trust that when you work with us, we’ll put in the time and effort to engineer your seals to the exact specifications, allowing for optimum performance on your project.

Is your project in need of a global diaphragm seal solution? We have the answer for you! Send our experts an email at sales@blissanandusa.com.

High Temperature Diaphragm Seal

For a long time, industry standard in fill fluid limits for diaphragm seals was 788°F (420°C). However, Concentrated Solar Power plants, which produce electricity by using mirrors to concentrate sunlight onto steam-producing receivers, use a Molten Salts Storage System that stores excess heat for nights and cloudy days. This technology can operate at temperatures as high as 1,022°F (550°C), creating a challenge for the existing fill-fluid temperature standards.

Bliss Anand-Badotherm have developed a patented High Temperature Diaphragm Seal (HTDS) that can withstand temperatures of up to 1,112°F (600°C). This seal can be used for both gauge and differential pressure transmitters.




  • Similar installation to standard Diaphragm Seals
  • Direct mounting process, reducing change of clogging
  • Gives accurate process information
  • Reduces change for possible air inclusion

Temperature and Static Pressure Limits

The maximum temperature limit for a diaphragm seal is typically determined by the fill fluid and the material of the body and bolts. We use AISI-321H for the body material and 1.4980 bolt material to ensure that our seals can withstand temperatures of up to 1,112°F (600°C). These materials are up to ASME B16.5 standards.

This table shows the temperature and pressure limits for three filling fluids:


Technical Specifications:

This table below shows the HTDS’s accuracy in GP and DP configurations, along with temperature effect and pressure details:


For more information, click here: htds-seal-solutions