Read our FAQ to learn more about Garlock products

Answer ... GYLON® 3500, 3504 , 3510, and 3522 are USP Class VI certified. For documentation, consult Garlock Application Engineering.
Answer ... Pumping the heat tracing pipe for solid materials at room temperature will bring a series of problems to the gasket:

1. Bolts are often hotter than flanges because heat is applied from outside the tube. This results in the bolt expanding more than the pipe, which reduces compressive stress on the gasket.

2. Any shut down pipes may condense solids. When the pipe is restarted while it is being heated, sometimes a solid blockage blocks a part of the pipe. Heating may cause some parts of the obstruction to dissolve and then swell. If a solid blockage blocks a part of the pipe, this expansion can create extremely high pressures inside the connection.
Answer ... We understand that many end users do not use torque wrenches for installation. We found that using a torque wrench is the easiest way to significantly improve gasket sealing performance. Any method that can properly control the compressive load on the gasket is acceptable.

For ANSI / ASME B16.5 raised flanges, see Bolt Torque Table in Engineering Gaskets Product Catalog. For non-standard flanges, consult Application Engineering.

The maximum torque value of glass-lined or PTFE-lined, FRP, PVC-type flanges is set by the flange manufacturer to avoid damage to the flange. We recommend using the maximum allowable torque for each size. These maximum torques are usually significantly lower than our recommended torques.
Answer ... Garlock recommends using thinner gaskets whenever possible. This not only reduces gasket costs, but also reduces emissions and material loss, and enhances blowout resistance and thus improves connection performance. Although thinner gaskets may not be as effective as thick gaskets when sealing many uneven flanges, thin gaskets are suitable for flatter flanges. In determining the thickness of the gasket, the experience of using the specific flange system is usually of great guiding significance. For this issue, we can provide a more comprehensive discussion.
Answer ... our application engineering department can provide relevant parameters.
Answer ... Steam exists in the factory in two forms: saturated steam and superheated steam. Saturated steam is standard boiler steam and has a defined temperature corresponding to each pressure. Superheated steam means that when corresponding to a particular pressure, its temperature is higher than the corresponding temperature obtained on the icon based on the saturated steam curve. We recommend ST-706 and GRAPH-LOCK® types for superheated steam. When you choose a gasket, pay attention to the pressure and P x T limits of each model. When approaching these limits, consult Garlock Engineering. See also the notes on steam service on each page of Fiber Gasket Technical Requirements.
Answer ... In some installations, thick gaskets are required to fill large gaps between flanges. We do not recommend stacking multiple gaskets in one flange. For example, when filling a gap with a thickness of 1/2 ", internal tests show that a better approach is to pad a 1/16" thick pad on each side of a 3/8 "incompressible spacer ring. Theoretically, the spacer ring must be consistent with the pipe metal, have a serrated surface finish similar to the flange, and be cut to the same size as the gasket. When using this method, we recommend a higher minimum Torque.
Answer ... For the correct storage conditions and expected shelf life of our products, Garlock has detailed instructions. They vary depending on the type of material. Available on request
Answer ... We are often asked about gasket reuse. We do not recommend this. When a gasket is compressed, its role is to fit the bumps on the flange surface, but when it is compressed, its sealing effect will be weakened. Gaskets containing rubber and gaskets that have been operated at high temperatures are less likely to reseal.
Answer ... To protect the environment, many new refrigerants have been put into use. CFC refrigerants have been gradually replaced by HCFCs and HFCs because they are thought to damage the ozone layer. See the chemical resistance chart for all refrigerants in the Engineering Gaskets product catalog. When the proportion of lubricants in the liquid composition is extremely low, compatibility with these refrigerants is hardly a problem.
Answer ... We are conducting gamma ray radiation tests on models 3000, 3200, 3400, 3700, 5500, 5507, 9800, 9850, 9920 and ST-706. These tests show that our non-asbestos pressed gaskets are resistant to approximately 5 x 107 rads of gamma radiation. Both GYLON® 3510 and 3545 have passed this test and are resistant to approximately 105 rads. We can provide test results.
Answer ... In any production line that pumps liquid, when the valve closes quickly and the liquid is nowhere to go, a very high instantaneous pressure is generated. The inertia of the fluid can also produce extremely high pressure spikes. These peaks appear too quickly, the pressure gauge cannot detect them at all, but may cause the gasket to blow out.
Answer ... The pH value is used to measure the pH of the solution. A pH reading of 7 is neutral and is neither acid nor alkaline. A reading of 1-2 indicates strong acid, and a reading of 13-14 indicates strong alkali or caustic medium.

Note: When choosing a gasket, it is not enough to have only one pH value without the name of the relevant chemical. Also, because the range of pH value counting method is very limited, the value of "1" or "14" can not fully explain all the acid-base concentrations. We need the concentration as a percentage. For example, the pH value of 4% sodium hydroxide is close to the upper limit of 14, which is the same as the 40% concentration reading.
Answer ... We recommend using GYLON® Model 3502, 3505, 3503 and Model 3562 and 3563 with embedded metal. These gaskets are specially manufactured and packaged to eliminate organic contamination. GRAPH-LOCK® type 3123 (maximum thickness 1/16 ") and type 3128 HOCH-DRUCK® are also acceptable.
Answer ... Some chemicals are considered strong oxidants and they can easily react with organic compounds. Among oxidants, we recommend using our GYLON® gaskets.
Answer ... Yes, Garlock has several gasket materials that are certified to meet any need. Model 3505 “Blue” GYLON®, MULTI-SWELL ™ Model 3760U, Model 98206 EPDM, STRESS SAVER® XP, and STRESS SAVER® 3505 and 3522 diaphragm models. See also Garlock NSF Manual
Answer ... Monomers are materials, such as styrene and vinyl chloride, which can self-assemble into polymers such as polystyrene and polyvinyl chloride. Because rubber-bonded gaskets are rarely compatible with monomers, we recommend GYLON® 3510 and 3530 gaskets. Under certain conditions, monomers can penetrate into the gasket and polymerize inside the gasket, causing the gasket to swell and occasionally burst. This effect is called the "popcorn effect". Applying additional compressive loads can reduce voids in the gasket, thereby reducing or even eliminating this effect.
Answer ... Some flange calculation programs require the modulus of elasticity of the gasket material. Since only rubber gaskets are truly elastic materials, other types of gaskets do not have a true elastic modulus. Garlock Application Engineering can provide a "compression vs. load" graph that can be converted into a calculated estimate for such calculations.
Answer ... Garlock has three sealing products that meet Navy technical requirements. Garlock 3125SS and 3200 are listed in the manual by Mil DTL-24696C, and STR-508 includes 9900 in the manual. These products are usually certified before being sold to the Navy or shipyard.

Because certification and specification requirements are constantly changing, every inquiry or order must be manually reviewed to verify compliance with certification and specification requirements and to ensure that orders are processed to customer requirements. The cost of certification and technical requirements will vary based on the number of bundles required to complete the order.
Answer ... See the Engineering Gaskets Catalog. These values are used in the ASME code for flange design of pressure vessels.

Note: Our tests show that as the thickness of the shim increases, the "M" and "Y" values also increase. This is the opposite of the trend stated in the ASME code. Studies on fugitive leaks and gasket ejection have verified this trend.
Answer ... The technical specifications of some pipes limit the maximum "leach" level of the gasket. These restrictions usually involve leaching of chlorides, fluorides, halogens. These ions or charged particles are also associated with restrictions, as they contribute to the potential for corrosion of the piping system. Garlock keeps the test results of many gasket models, and we will test and prove the product's leachable chloride as needed. These tests are all charge tests. Due to the nature of this type of test, we only publish some extractables of "typical" models, such as our nuclear grade 9920.
Answer ... jet fuel is usually a petroleum refining product similar to kerosene. We recommend using GYLON®, nitrile rubber bonded pressed sheet and GRAPH-LOCK® products.
Answer ... Customers sometimes require flange insulation or insulation components or gaskets to insulate two mating flanges. Many distributors sell kits that include insulating gaskets, bolt sleeves, and insulating washers under steel washers and nuts.

Garlock currently does not sell kits, however, we offer many gasket types with excellent electrical insulation (please ask the Application Engineering Department for dielectric breakdown voltage values).
Answer ... Garlock highly recommends using a calibrated torque wrench to tighten the bolts to the correct load. We can provide installation procedures and details on request.
Answer ... gasoline gasoline is a mixture of gasoline and ethanol (usually 10-15% ethanol). GYLON® series gaskets are preferred; nitrile rubber bonded pressed gaskets are also available; most rubber gaskets are not recommended.
Answer ... Shims installed in grooved or tongue-and-groove flanges require additional consideration: The compressed height of the gasket must be considered. It is especially important that we use highly compressible gaskets such as one of the GYLON® 3545 and 3540 GRAPH-LOCK® types instead of compression gaskets. When the flanges contact each other, the fully compressed thickness (not the original thickness) must be greater than the groove depth or the gap between the tongue and groove. Ideally, the tenon height should be at least the same as the groove depth.
The ASME and ASTM committees are working to develop a new system and a new coefficient system for use in the calculation of ASME code flange designs. These new constants (also known as Gb, Gs, and a) suggest leakage rates at installation and compression with negative losses, so they help the end user design to achieve a certain level of leakage. The use of limiting leakage rates generally creates a high demand for flange bolt loads, which will improve the connection performance of the designed flange. For gasket constant values, see the Engineering Gaskets Product Catalog.
Answer ... Full-face gaskets cover the entire flange surface and include screw holes. They are usually used in flat flanges. Convex flanges usually use ring gaskets. See also: How does flange type affect gasket selection?
Answer ... The chemical agent MTBE (methyl tert-butyl ether) has become a very common fuel additive, and people often ask about the compatibility of this material with gaskets. Garlock internal testing has shown that GYLON® gaskets are not affected by MTBE. We have also proven that Type 9850 and 3000 Pressed Gaskets are also suitable for MTBE applications. We recommend using these materials in MTBE or MTBE mixed with gasoline applications.
Answer ... Where conditions permit, we recommend using a round head cutter with a radius of 1/16 "to produce 30-55 concentric circles or helical serrations per inch on the flange surface. This finish is usually difficult This cannot be achieved in non-circular flanges. We recommend multi-directional graining for non-serrated surfaces and a roughness of 125-250 microinch RMS.
Answer ... Flange has various shapes and sizes, and the type of flange used in actual working conditions has a significant impact on the recommendation of gasket material. Standard ANSI raised flanges are perfect for use with our pressed fibers and GYLON® gaskets. Elastomer (rubber) gaskets can be crushed in such flanges.

Non-metallic flat flanges work best with elastomeric (rubber) gaskets, such as various STRESS SAVER® gaskets. The GYLON® 3545 is also suitable for some applications. Compression fibers and standard GYLON® are frequently used in all-plane carbon steel flanges, but the compressive stress on these flanges is well below our recommended minimum compressive stress. Therefore, the amount of compression of the gasket is small; if there is unevenness on the flange surface, the gasket may not achieve the sealing effect. Because the leakage rate of the gasket depends on the compressive stress used, the tightness of the connection may not be as expected by the customer.

Glass lined flanges are used in many chemical applications. Because these flanges often have "corrugations" when firing, it is recommended to choose the softer GYLON® series, such as 3545, 3565, and 3504. Before ordering the gaskets, the gap between the flanges placed apart must be measured. Gasket thickness should be four to five times the maximum gap measured.

Stainless steel (SS) flanges are common in many factory chemical applications, and low-strength stainless steel bolts are often used. Considering the chemical nature and the low pressure stress of the bolts, 3545, 3565 and 3504 are generally recommended. Nevertheless, we still recommend the use of high strength, strain hardened stainless steel bolts. Due to the very small amount of chloride that can be filtered out, the 3000, 98206 and Stress Saver XP models are preferred for stainless steel flanges. See Stress Saver XP in the Engineering Gasket Catalog. When considering other models, consult Garlock Engineering.
Answer ... Garlock has developed a fire test standard in accordance with Industrial Fire Test APIs 589 and 607. Types G-9900, 9800, 9850, ST-706, IFG® 5500 and GRAPH-LOCK® all pass this fire test. We can provide test procedures and results as needed.
Answer ... Models 3500 (tan) and 3510 (white) comply with FDA regulation 21CFR177.1550. Their composition and precipitates are required. Fillers are also acceptable under 21CFR177.2600, and pigments (if used) are also 21CFR178.3297 compliant. The trademark ink complies with 21CFR175.300. The Model 3500 (Tawny) is USDA approved for direct contact with meat and poultry applications.

Models 3504 (blue), 3565 (ENVELON®) and 3594 (green) are all FDA-compliant 21CFR177.1550. They meet the composition and precipitate requirements. Fillers are listed in the US Food Chemical Code (FCC 3rd Edition) and are GRAS (Generally Recognized Safety Class Additives-21CFR170.30). The trademark ink complies with 21CFR175.300.

Type 3522 (transparent) complies with FDA standard 21CFR177.1550.

The components of Type 3540 (microgrid) and Type 3545 (microgrid with hard center layer) are in compliance with FDA standards 21CFR177.1550, 21CFR182.1, 21CFR182.1217 and 21CFR175.300. The trademark ink complies with 21CFR175.300.

The PTFE resin used in Type 3535 PTFE bonded sealants complies with FDA standard 21CFR177.1550. The PSA tape used to hold the joint sealant in place conforms to standard 21CFR175.105.
Answer ... It is significant to limit the leakage of various chemicals and other substances to the requirements of the United States Clean Air Act. Garlock has been tested in this regard and can provide reports on the effect of gasket type, compressive load, internal pressure, and flange finish on fugitive levels upon your request. The use of heavy-duty flanges wherever possible and the selection of high-quality gasket materials with good sealing performance are the easiest ways to reduce emissions.
Answer ... Garlock can provide insulation breakdown voltage test data for the most common gasket types. Generally speaking, the GYLON® series and compressed sheets without carbon or graphite fibers have a relatively high dielectric breakdown value. In wet or humid environments, the 3504 and 3565 models have very good dielectric breakdown resistance. It is worth noting that not all rubber materials are insulated.
Answer ... Many applications require low conductivity of the gasket. In some applications, electrical current is applied to the pipes to prevent corrosion; in other cases, the customer makes sure that flanges made of different metals do not react with each other.
Answer ... We recommend using the GYLON® series at temperatures as low as -450 ° F (-268 ° C), and we generally recommend using pressed gaskets at temperatures as low as -100 ° F (-75 ° C).
Answer ... For pressed fiber gaskets and GYLON® gaskets, Garlock recommends a maximum compressive stress of 15,000 psi, while GRAPH-LOCK® and MULTI-SWELL gaskets recommend a maximum compression force of 10,000 psi. The actual crush strength of these materials is usually higher. For rubber materials with Shore A below 70, the maximum compressive force is 900 psi; for rubber materials with Shore A above 70, the maximum compressive force is 1200 psi.
Answer ... The compressive stress must be appropriate for the type of gasket. For situations where the compressive stress is too low or too high, see the notes below.

Insufficient compressive stress: Compared with gaskets under appropriate compressive stress, gaskets with too low compressive stress have higher leakage rates and poor blowout resistance. This will severely affect performance and frequently cause connection problems.

Excessive compressive stress: Excessive compressive stress can cause chipping, which can accelerate gasket aging and even cause immediate failure.

Uneven compressive stress: Gaskets prevent blow-out by friction between them and the flange. In the initial and use process, the higher the compression load, the higher the blowout resistance. When the compressive stress of the connecting flange is not uniform, the low compression area will become the main part of the gasket blowing out.
Answer ... For a specific type of gasket, its compressibility depends on its compressible data and application load. Inadequate compressive loads often cause sealing problems. We can provide the compression and load comparison table for common gasket types as required. In applications requiring small internal clearances, such as split pumps, small tolerance washers should be considered.
Answer ... We recommend using GYLON® gaskets in chlorine service. The gasket type is selected according to the condition of the flange. Model 3510 has been incorporated into the Chlorine Association Specification Rule 95, and Garlock metal gaskets have also been incorporated, including GRAPHONIC® gaskets.
Answer ... Some end users perform a bubble test on their system to check the tightness of the gasket. This information is very useful before specifying a type of gasket. For gasket connection, the bubble test is a very strict test, but this method is not suitable for verifying that the gasket is properly installed. Light flanges that are only subjected to low compression loads may never achieve the "bubble seal" result.
Answer ... GYLON® 3522 meets 3A requirements. For documentation, consult Garlock Application Engineering.
Answer ... ABS is short for American Bureau of Shipping
The following Garlock models are certified by the American Bureau of Shipping:

• 706 • MULTISWELL 3760 • BLUE-GARD® 3000, 3200 • GRAPH-LOCK® 3128, 3125SS, 3125TC • GYLON® 3500, 3504, 3510, 3545 • 5500 * • 8459 ** • 9900 *
Answer ... Although we recommend using original anti-adhesive mounting gaskets, other anti-adhesives have proven to be very useful in certain situations, such as where flanges cannot be easily separated. The coating should be as thin as possible. We strongly recommend the use of dry powder rather than paste and grease based adhesives. This can greatly reduce the compressive strength and blowout resistance of the gasket. In addition, paste-like or grease-like materials may deteriorate or dissolve during use, which may leave channels on the gasket that may cause leakage.
The answer ... High-octane gasoline is used in propeller aircraft engines. Instead, jet fuel is used in jet engines. In aviation gasoline, the percentage of aromatics is high. GYLON® is the preferred gasket; pressed gaskets containing nitrile rubber adhesives can also be used successfully in some applications. If you are unsure, consult Garlock Engineering.
Dial-up navigation text messages