How to Change a Gauge Protector for a Rubber Cup Diaphragm?

The regular maintenance of gauge protectors is crucial to ensure they successfully fulfill their purpose of sensing pressure, smoothly. The purpose of the rubber cups is to sense this pressure and protect sensitive gauge internals from harsh drilling fluids, mud or cement. Regular maintenance of this gauge protector promises a lengthy stress-free service in the field.


The gauge protector comes with a rubber cup diaphragm. The rubber cups protect the gauge internals from harsh drilling fluids and senses pressure to transmit it to the gauge. When the rubber cup becomes worn, damaged, or blown, it will need to be replaced.


If a diaphragm cup (sometimes called a bladder) wears or blows, it could harm the bourdon tube and/or movement as the drilling fluids can enter the gauge. Inspecting the rubber cup during regularly scheduled maintenance will prolong the life of the gauge.


How to Check If The Rubber Diaphragm Needs A Replacement?             

Begin with checking the diaphragm cup’s round end. If there is a small hole in this area, the system will consequently lose fluid and fill with air instead. If the system has been compromised, the rubber cup sides will fill up like a balloon, in turn, allowing the drilling fluids into the system.  When examining the system make sure that the retainer nut is flush with the housing.  If the retainer nut is not flush, the diaphragm cup will display a cut on the lip. If cuts, wear, or tears are found on investigation then it’s time to replace the diaphragm cup.


Important Safety Notice

Given that we couldn’t possibly assess every factor or the outcome of the investigation, some warnings against the use of specific service methods stated in these methods /guide can damage the equipment or render them unsafe or could have possible hazardous consequences. Keeping this in mind, we urge you to read further.


What You’ll Need


1.Needle Nose Pliers

2.Retainer Nut


4.Diaphragm Cup

5.Retainer Nut Wrench

6.Diaphragm Protector


Here is a step by step method of how you can replace a rubber diaphragm in gauge protector:


Step One: Flip the Unitized Mud Gauge (UMG) on the side with the gauge face down in a vice to expose the base of the flange. The gauge should be placed upside down so that the glass stays protected during the removal of the diaphragm.


Step Two: With the help of a 1/2″ ratchet with no socket, place ratchet into the center hole in the bottom of the flange.


Step Three: Loosen the retainer nut which holds rubber diaphragm in place by making use of a ratchet then finish off by loosening the nut by hand and removing it.


Step Four: Slide a flat-head screwdriver between the rubber diaphragm cup and the diaphragm housing wall. Making use of the screwdriver, pull the rubber cup diaphragm away from the wall of the gauge protector housing.


Step Five: On achieving a gap large enough, grab the lower rim of the diaphragm using a pair of needle nose pliers. Pull the diaphragm to remove it. If the diaphragm has ruptured, make sure you replace all the pieces.


Step Six: Turn the gauge back on side to expose the center hole. Insert the new rubber cup diaphragm into housing. Ensure you place the closed-in top into the housing first, with the larger rubber cup opening going into housing last. Secure it into the hole until it fits perfectly. The diaphragm will rest in the grove located near the opening and will give a slight pop when back in place.


Step Seven: Replace the retainer nut and finger tighten it in place. Grease retainer nut threads and lip with silicon-based grease to keep the retainer nut from cutting or tearing the rubber cup diaphragm.


Step Eight: Ensure that the retainer nut is sitting just below the lip of gauge protector housing (below flush). Using a ratchet, tighten retainer nut in place. Make sure you don’t over tighten the retainer. Overtightening retainer nut could potentially reduce gauge accuracy and/or destroy rubber cup diaphragm.


To maintain the life of a gauge, regular inspection and the timely replacement of the rubber diaphragm is essential. With regular maintenance, this gauge protector will successfully provide years of worry-free service in the field.


A Guide to Choosing O-Rings Based on Material Makeup

O-rings are a common application in the manufacturing industry. Factors like cost, simple production, easy installation, and pressure resistance, allow wide application in common products, such as automobiles and engines. O-rings are commonly used in the aerospace industry in many types of rockets.


The diverse scope of material used in the fabrication of O-rings allows for wide application across industries. They are made from rubber, or, more specifically elastic polymers, or elastomers. These polymers are cured, often through the process of vulcanization, transforming them into stronger and highly durable elastic rubber. The material differs in terms of different properties i.e. some materials are more elastic while some are more tear resistant.


With the range of materials available, choosing the correct material as per the application can get confusing. Because of these polymers are cured, often through the process of vulcanization, transforming them into strong, durable and more elastic rubber. Keeping in mind the many efficiencies and deficiencies that can guide or influence that decision as well taking the help of designers and contractors can help make a decision, there are many efficiencies and deficiencies that can guide or influence that decision as well. Here are some of them:


  • 1. Nitrile (Buna-N)

    Temperature range:
    -65 degrees ºF – 300 degrees ºF .

    Suited for:
    Buna-N is resistant to tears and abrasive treatment.  These general purpose seal are best suited for petroleum oils, water, and some hydraulic fluids.Deficiencies: Problems can arise with automotive brake fluid, ketones, phosphate ester hydraulic fluids, and nitro and halogenated hydrocarbons. Even though it is ozone and weather resistant, this resistance is not infallible but can be supported through compounding.Applications: Nitrile works well for applications that have limited temperature and resistance requirements.


  • 2. Ethylene Propylene Rubber (EPR)Temperature range: -65 degrees ºF and 300 degrees ºFSuited for: Skydrol, a hydraulic fluid with a noxious smell and can irritate the skin, and its corrosive properties can be damage equipment. EPR o-rings work well with Skydrol as well as other hydraulic fluids, as well as water, silicone oils, steam brake fluids, and alcohols.Deficiencies: Like Nitrile, EPR is not foolproof for a range of applications due to wear and tear issues.Applications: EPR o-rings are used in hydraulic pumps in the aerospace industry.


  • 3. Fluorocarbon (Viton)Suited for: Fluorocarbon is an all-around material that can handle a number of applications, especially diverse sealing jobs that involve movement. It is also suited for petroleum oils, silicone fluids and gases, acids and some halogenated hydrocarbons, like carbon tetrachloride.Deficiencies: Fluorocarbon is not recommended for Skydrol, amines, esters, and ethers with low molecular weight and hot hydrofluoric acids.Applications: Fluorocarbon o-rings are very versatile, and features in many different automotive, appliance and chemical processing industries.


  • 4. NeopreneTemperature range: -65 degrees ºF and 300 degrees ºF.Suited for: Neoprene seal refrigerants in refrigeration and air conditioner units, petroleum oils and mild acid resistance silicate ester lubricants.Deficiencies: Finished neoprene products are often compounded with lead-based agents, that could be hazardous to human health. Some people tend to be allergic to neoprene. It has a low resistance to petroleum lubricants and oxygen.Applications: Neoprene performs well in refrigeration units of air conditioning systems.


  • 5. PolyurethaneTemperature range: Between -65 degrees ºF – 212 degrees ºF.Suited for: Polyurethane features abrasion and extrusion resistance, as well as general toughness.Deficiencies: Applications requiring good compression and heat resistance would not be suitable for polyurethane.Applications: Polyurethane o-rings are used for applications like hydraulic fittings, cylinders and valves, pneumatic tools, and firearms.


  • 6. SiliconeTemperature range: -120 degrees ºF -450 degrees ºF, although silicone o-rings are known to withstand -175 degrees ºF during short periods of exposure.Deficiencies: Silicone means they are better suited for static applications than dynamic. They do perform well with water, steam or petroleum fluids, either.Applications: Silicone o-rings can be used in  High-temperature fuel injection ports.


  • 7. PTFETemperature range: -100 degrees ºF -500 degrees ºF.Suited for: PTFE encapsulated o-rings manage to handle surface wear well, as well as exhibiting corrosion and abrasion resistance, non-permeability, chemical inertness, and low absorption.Deficiencies: PTFE is rigid and best suited for static applications.Applications: PTFE O-ring applications include automotive steering devices and paint guns.

Diaphragm Valves vs Electrically Actuated Control Valves

What are Diaphragm Valves?


Diaphragm valves are named after a flexible disc that is connected with a platform at the top of the valve body, which in turn, forms a seal. A diaphragm is an adaptable component that responds to pressure and engages a force to open, close and control a valve.


Diaphragm valves use a durable diaphragm that is connected to the compressor by a stud, which is proceeded by being shaped into the diaphragm. The diaphragm is shoved, making contact with the bottom of the valve body, to shut-off as an alternative, instead of tweaking the liner closed to shut it off. Diaphragm valves are manually operated and are ideal to control the flow control by offering a variable and precise opening for handling pressure drop through the valve. A handwheel is turned until the desired amount of medium flow is transmitted throughout the system. The handwheel is in motion until the compressor pushes the diaphragm to counter the bottom of the valve body to either halt the flow or make way in the bottom until there is a passage for flow.


The diaphragm is secured to a compressor by a stud constructed inside the apparatus. The valve stem is moved up to start or enhance the flow in the compressor. To stop or reduce the flow, the compressor is modulated along with the diaphragm being thrust against the foot of the valves. Diaphragm valves are reliable for managing the flow of liquids containing solid matter and have the ability to be fixed in any position.



What are Electrically Actuated Control Valves?


There are two types of electric valve actuators; rotary and linear. Each of them uses special valves to function.


The motor varies in voltage and puts a lot of emphasis on torque generation. To avoid heat damage from excessive functions or override current draw, electric actuator motors come along with a sensor which marks an increase in temperature in the motor mechanisms. The sensor gives out a signal when the circuit needs to be opened when overheated. The circuit can be closed again when the motor reaches a moderate temperature.


Electric actuators are dependent on a gear train attached directly to the motor to boost the motor speed which navigates the speed of the device. You can change the output speed by installing a cycle length control variable.



Why are Electrically Actuated Control Valves better?


– You do not need an air supply. Air supply may not be available in many places and it is also hard to keep track on.


– Colder climates can cause compressed air systems to freeze or clog but the electrically actuated controlled valves have the ability to withstand these temperatures.


– They are cost effective.

HNBR seals – Pushing Boundaries for the Energy, Oil, & Gas Industry

HNBR Seals

When it comes to aggressive EOG  environments that require extreme reliability, longevity, and durability, one elastomer comes to mind: Hydrogenated Nitrile Butadiene Rubber (HNBR). HNBR is renowned for its durability and retention of properties after overtime exposure to external elements like heat, oil, and chemicals that tend to weaken the durability of rubber seals.


Properties of HNBR


Hydrogenated Nitrile Butadiene Rubber (HNBR), is a variant of nitrile rubber (NBR) that has been hydrogenated to give it enhanced mechanical characteristics and, help in increasing resistance to wear and tear. The properties of hydrogenated nitrile rubber (HNBR) depend upon the acrylonitrile content (ACN) and the degree of hydrogenation of the butadiene copolymer. The fluid and chemical resistance improves as the ACN content is increased. The preceding improvements to the material properties over that of nitrile rubber (NBR) include greater thermal stability (up to 149°C/300°F, with short periods at higher temperatures), broader chemical resistance, and greater tensile strength.


Benefits of HNBR over the standard Nitrile and Fluorocarbons

1. HNBR Seals have enhanced resistance to environments that are prone to ozone and weathering, industrial lubricants, amine-based corrosion inhibitors, sour gases (H2S), and hot water/steam (150°C).

2. Maximum operating temperature +56°F (180ºC) in oil +320°F (160ºC) in air.

3. Minimum operating temperature -25ºF (-26°C) special grades –50°F (-45°C)

4. Minimum operations are much more competitive compared to existing technologies and lead to cost reducing, technical parameters improving, also strength increasing, and the better and more qualitative product.

5. Excellent aliphatic (not aromatic) hydrocarbon resistance.

6. Fit for use in methanol and sour environments, (up to 5% Hydrogen Sulfide)


Application Advantages of HNBR Seals in the Energy, Oil, & Gas Industry

HNBR seals should be considered over standard Nitriles and Fluorocarbon seals in selected applications for the following advantages:


Improved High-temperature Resistance


HNBR seals have excellent oil and fuel resistance along with superior mechanical properties and can sustain higher operating temperatures; up to 356ºF when immersed in oil.  Based on the compound formulation, standard nitriles can endure a temperature ranging between 200° and 300°F. Fluorocarbons in hot water/steam tend to dissolve its mechanical properties.


Resistance to Sour Crude


Oil and gas that contains hydrogen sulfide (H2S) can cause a substantial decrease in tensile, elongation and hardness properties in standard nitrile
and fluorocarbon seals. Tests conducted have proved that HNBR seals promise stronger resistance over standard nitriles and fluorocarbon when directly in contact with heat, aggressive fluids, and corrosive chemicals.
Explosive Decompression Resistance


The compression-set resistance of HSN at high temperatures (such as 302°F) is much better than standard nitriles. Fluorocarbons show signs of compression at temperatures as low as 0°F.


Resistance to Corrosion Inhibitors


Corrosion inhibitors with standard nitriles and fluorocarbons create increased elongation, loss of elasticity and rigidity. On the other hand, HNBR seals have a higher resistance to a variety of common corrosion inhibitors.


Resistance to Explosive Decompression


Explosive decompression occurs when gas at high pressure permeates into the elastomer. Nitriles and fluorocarbons have shown lesser resistance to high-pressure CO2, as compared to HNBR.


Cost-Effective Bridge Between Nitrile Rubber (NBRs) and (per) Fluoroelastomers (FMKs)


HNBR elastomers offer optimum performance at a cost between nitrile rubber (NBRs) and (per) fluoroelastomers (FMKs). HNBR seals bridge the gap between the two elastomers in many areas of application where resistance to heat and aggressive media are required simultaneously.


HNBR seals boast of invaluable properties like high durability, tensile strength, and outstanding abrasion resistance that push the performance boundaries of elastomers in the aggressive EOG environment, therefore, giving impetus to the keep up with the continuous innovation in the Energy, Oil, & Gas Industry.

What is a Viton® (FKM) Gasket & What are its Applications?

Many of the most challenging sealing applications require a heavy-duty gasket that can perform exceptionally well in the harshest of conditions. Such applications often call for gaskets made from a family of fluoroelastomers called FKM. While Viton® is the generic name for FKM, it actually is a brand name of DuPont for its synthetic rubber and fluoropolymer elastomer.


What Exactly is FKM?

The FKM family of elastomers consist of copolymers or terpolymers of tetrafluoroethylene (TFE), vinylidene fluoride (VDF) and hexafluoropropylene (HFP), hexafluoropropylene (HFP) and vinylidene fluoride (VDF or VF2) and perfluoromethylvinylether (PMVE). Since DuPont was the first company to really market this material, its brand name Viton® has become the most commonly associated name with FKM.


Majority of synthetic rubbers are composed of long chains of carbon and hydrogen atoms. These rubbers are prone to swelling upon exposure to oil and have a limited temperature range. What’s more, they break down over time with UV exposure (through sunlight).


When fluorine is added to synthetic rubbers, it bonds tightly to the carbon atoms and makes the compound more resistant to other compounds while providing tremendous flexibility. This changes the properties of the material and makes FKM the high-performance rubber compound that is crucial to many applications.


FKM is known for excellent resistance to heat, chemicals, concentrated acids, oils, and aggressive fuels.


Material Grades for Viton® Gaskets

On the basis of material composition and applications, FKM comes in a number of different material grades. Some of these are:


General Use Grades:


Viton® A

Viton® A dipolymers are polymerized from two monomers – vinylidene fluoride (VF2) and hexafluoropropylene (HFP). It is the most widely used Viton® gasket material and has applications as rubber seals for aerospace and automotive lubricants and fuels.


Viton® B

Viton® B is a terpolymer, i.e. polymerized from three monomers – vinylidene (VF2), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE). This material is primarily used in chemical processing, power industries, and utilities.


Viton® F

Viton® F is also a terpolymer, polymerized from three monomers – vinyl fluoride (VF2), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE). F types offer the best fluid resistance out of all other Viton® types. They are extremely useful in applications that require resistance to fuel permeation.


High-performance Grades:


Viton® GB and GBL

Viton GB and GBL are fluoroelastomer terpolymers that are polymerized from three monomers – vinyl fluoride (VF2), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE). These fluoroelastomers use peroxide cure chemistry that leads to a superior resistance to acid, steam, and aggressive engine oils.


Viton® GLT

This fluoroelastomer is specially designed to retain the high heat and chemical resistance properties of general use Viton® grades while improving the low-temperature flexibility. Also, Viton® GLT offers an 8 to 12°C lower glass transition temperature, which is indicative of low-temperature performance in elastomer applications.


Key Properties of a Viton® Gasket

When it comes to gasket materials, good compression set resistance or the ability to spring back after the load is taken off is needed. Other desirable properties include a wide temperature range and good chemical resistance. FKM offers exceptional performance in all these regards.


FKM is graded as ‘HK’ as per the ASTM D2000 standard for classifying elastomers. Here, H indicates that the performance of an FKM Gasket deteriorates very little after prolonged exposure to temperatures of 250°C (480°F). FKM also works well in low-temperature conditions going as low as -40°C (-40°F).


Whereas, the K indicates the resistance to swelling. Since K is the lowest possible rating, it means that FKM swells less than almost all other elastomeric materials. FKM is also highly resistant to chemicals and can withstand ozone, typical automotive fuels, and hydrocarbon lubricating oils. However, FKM doesn’t give as great results against strong acids, alkalis, and ketones.


Applications of Viton® for Rubber Gaskets

Viton® gaskets were first used in the aerospace industry owing to their fuel resistance and low burning characteristics. Now, their application can be found in fluid power, automotive, appliance, and chemical industries. Moreover, with the introduction of FDA grades, the uses of FKM have been extended to the food processing and pharmaceutical industries as well.


Viton® Gaskets are highly recommended for harsh, high-temperature environments. They are often used with lubricating and fuel oils, gasoline, vegetable oils, alcohols, diluted acids, hydraulic oil, and kerosene because of their chemical resistance. In addition, Viton® applications can also be found in fuel seals, cap seals, T-seals, and radial lip seals in pumps. FKM gaskets also offer superior UV resistance that makes them a great choice in applications where prolonged sunlight exposure is expected.


We hope that you found this information useful. If you’re looking for FKM or Viton® gaskets for your application, Harkesh Rubber manufactures top-of-the-line products to fulfil your sealing needs. In fact, we can produce low-temperature FKM gaskets that can withstand up to -50°C! Simply contact us for your Viton® gaskets needs.


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