Gold Coated Monel Diaphragm Seals

Bliss -Badotherm Americas  

provided special solution for HF Aky application by replacing SS316 with Monel Diaphragm seals having  40 Microns GOLD COATING.

Served this unique Edge solutions to Shell, Total, Sapref etc…Badotherm Diaphragm Seal Solution Gold Coating

IMG_1626spirit to walk an extra mile




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

Diaphragm Seal Repair

Diaphragm Seals are typically used with pressure transmitters, but can also be used with pressure gauges and pressure switches. They are recommended in applications where the process medium is:

  • is aggressive, corrosive, toxic and/or highly viscous
  • has a (extremely) high or low temperature
  • has crystallization and/or polymerization

Given the above applications, seals are often subjected to harsh environments, rendering them damaged. High temperatures can ruin seals by heating fill fluids. High pressure water jets, corrosive materials and dents can also cause damage.


Bliss Anand understands that constantly replacing your diaphragm seals can get expensive, so we offer Diaphragm Seal Refurbishment Services. We will replace an old Diaphragm Seal from an existing transmitter-seal assembly at half the cost of a new transmitter-seal assembly, so you can get your project running smoothly again with minimal disturbance.

Benefits of Seal Renewal


  • Significantly more economic than ordering a completely new instrument
  • Before executing the order, the transmitter is tested for proper functioning, so there are no unnecessary costs for a repair executed in vain
  • All brands of pressure transmitters are compatible and new Diaphragm Seals can be mounted to them
  • A clear and written quotation, so you have a clear insight in the costs and actions beforehand
  • A repair/renewal of Diaphragm Seals often provides valuable information regarding the process and offers the opportunity of a better solution for increased lifetime

For more information, download our catalogue: Badotherm Diaphragm Seals Repair Service or call us at 281.479.2457 if you have questions about Diaphragm Seal Refurbishment.

Low Gauge Pressure Diaphragm Seals

Standard diaphragm seals limit you to measuring down to 100mbar. Beyond this, measurements are inaccurate and often not possible at all.

This can be problematic when trying to measure lower pressure applications, so we are offering you a solution – our Low Gauge Pressure Seals, developed for measuring pressures as low as 5mbar with minimal temperature effects.

Screen Shot 2017-05-22 at 11.20.16 AM

Typically, in order to obtain low-pressure readings in applications, nitrogen blankets are used to prevent process gases from entering the atmosphere. You need to be able to accurately measure and monitor the pressure of the nitrogen blanket in order to minimize its interference with the process in the vessel.

Unfortunately, nitrogen blankets with an overpressure are unstable in a corrosive environment that uses diaphragm seals. The combination of the seal and the low overpressure range (approximately 10mbar for nitrogen blankets) results in high temperature effects when exposed to process and ambient conditions. The high temperature effects then lead to unreliable and unstable data.

With the Low Gauge Pressure Diaphragm Seal, the minimum GP range reduces from 80 mbar with a standard Diaphragm Seal to only 5 mbar with the LGP Diaphragm Seal. Similarly the ambient temperature effect reduces from 0.006 psi (0.4 mbar) per 50°F (10°C) to 0.0004 psi (0.03 mbar) per 50°F (10°C), while the process temperature effect reduces from 0.006 psi (0.39 mbar) to 0.001 psi (0.09 mbar).Screen Shot 2017-05-22 at 11.20.26 AM

The LGP Diaphragm Seal also provides additional benefits:

  • The way of mounting the transmitter to the vessels has no effect on the zero and span adjustments of the transmitter, so there is no zero adjustment required
  • There is no effect on the performance by a change in the density of the fluid caused by ambient temperature fluctuations; so there is no mounting effect.

For more information, please download the LGP Diaphragm Seal brochure here: Badotherm Diaphragm Seal Solution Low Gauge Pressure (LGP)

PTH Diaphragm Seals

Screen Shot 2017-03-07 at 1.56.46 PMPTH Diaphragm Seals were designed as an alternative to the existing Rosemount High Process Temperature Transmitter. The seal, which can be directly mounted onto a transmitter without the use of remote seals or capillaries, can go up to temperatures as high as 392°F (200°C), though by using different fill fluids the temperature can go even higher, up to 788°F (420°C). This solution makes it possible to measure differential or gauge pressure at high process temperatures through a direct mounted seal.

The PTH Seal is designed and manufactured to meet the requirements of IEC 61518, with all the wetted parts constructed from AISI 316 (L).



Maximum Temperature
Using BSO-22, the maximum process temperature it can withstand is 392°F (200°C). In combination with other filling fluids, the maximum process temperature can increase to 788°F (420°C).

Maximum Static Pressure

  • 200 bar / 392°F (200°C)
  • 250 bar / 68°F (20°C)
  • 350 bar / 68°F (20°C) (design)

Reference Accuracy
0,025% for the Diaphragm Seal + transmitter specifications

Mounting Position Effects
Zero shifts up to 15 mbar (at 180°C), which can be calibrated out. There is no span effect.

The PTH dimensions are designed according to the IEC standard 61518 and the seal is suitable for mounting to the process connectors according the DIN19213 1982 part 2 for manifold mounts.

Special Materials and CoatingsScreen Shot 2017-03-07 at 1.58.26 PM
The PTH Seal can be supplied with various exotic
diaphragm materials, including Hastelloy C276, Monel or Tantalum. The process flanges can also be supplied with these exotic materials. Other materials are available on request.

For Hydrogen applications, the PTH Seal Diaphragm can be Gold Coated.


Temperature Effect

Options Temperature effect
Standard 0,24 mbar / Δ50°F
With temperature test 0,15 mbar / Δ50°F

Temperature Limits

Filling fluid Temperature specifications
BSO-22 (standard) -40°F to 392°F
BSO-40 (FDA approved)    5°F to 455°F
BSO-18 14°F to 599°F
BSO-42 14°F to 662°F
BSO-48 -4°F to 788°F


Gold Coated Diaphragm Seals

Hydrogen is not typically considered corrosive, but as a common element in diaphragm seal applications, there are certain circumstances where it may cause issues. For these times, Bliss Anand America and Badotherm Netherlands offer you a solution – Gold Coated Diaphragm Seals. The gold protects the fill fluid from becoming saturated with hydrogen, leading to more accurate measurement for your project.

So what is hydrogen permeation?

Hydrogen is usually found is a diatomic state, as two hydrogen atoms, or H2. These molecules do not permeate a regular sized diaphragm, at a standard thickness of 75 μm. However, under certain pressures and temperatures, the diatomic hydrogen splits into two H+ ions that are smaller than the space between the molecules of the material used to construct a regular diaphragm. This allows the H+ ions to slip between the cracks. Having permeated the diaphragm, the H+ icons join back into H2, dissolving into, and eventually saturating, the fill fluid. Over time, hydrogen gas bubbles form, altering the performance of the mounted transmitter.


The Bliss Anand America – Badotherm Netherlands Solution

Gold is a noble metal, which means it is more resistant to corrosion than most other materials. Adding a layer of gold to a base metal provides an extra layer of protection to the seal. The H+ ions are not able to permeate the gold diaphragm foil, allowing your fill fluid to remain pure.


We take our seals the extra mile beyond our competition, and for increased security at extreme conditions, we offer 40µm thickness that can withstand temperatures up to 752 °F (400 °C). This design is approved by international end-users including Royal Dutch Shell.

Gold also increases the chemical resistance of the seals, and can therefore be used in multiple ways:screen-shot-2017-02-06-at-12-42-40-pm

  • To protect against hydrogen permeation, as described above, only the diaphragm is coated.
  • To increase chemical resistance, the coating can be extended to the outside diameter of the gasket surface.


Do your diaphragm seals need the gold standard of protection? Download a brochure here for more information or give us a call at 281.479.2547 to speak to our sales team.


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