Plumbing gaskets: types, materials and sizes

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The most common cause of plumbing malfunctions is a worn out or incorrectly installed gasket. It is not difficult to cope with the problem, but at the same time you need to choose a truly high-quality and reliable product. And this can be done only in a store that buys gaskets in bulk from a manufacturer from a reliable supplier, for example, from the MasterProf Company. But first you need to navigate the assortment, having learned what sealing products there are, and which of them should be chosen in each particular case.

Gasket types

Gaskets differ in the material from which they are made. In addition to popular rubber products, the modern market (including suppliers offering wholesale plumbing gaskets) offers consumers fluoroplastic, paronite, silicone rings, as well as fiber gaskets.

Gaskets can also have different purposes:

  • for heated towel rails;
  • for divertors;
  • for mixers;
  • for heating radiators;
  • for ceramic or classic tap valve, etc.

Experts recommend choosing a suitable seal material first, because this criterion is one of the most important.

MasterProf Company uses materials of different quality for the production of plumbing gaskets. GOST standard quality products are made from Russian raw materials and sold under the MasterProf brand. Also, in parallel, high-quality products are produced from Italian raw materials. This type of gasket is marketed under the MPF brand.

Rubber plumbing gaskets

Gaskets made of rubber are relatively cheap and do not impose special requirements on the surface of the parts to be joined. It is recommended to install them in systems with the pressure not exceeding 10 bar. The limitation on the temperature of the application does not allow their use in heating systems.

Today, these products are considered the most common, so many companies are engaged in the production of rubber gaskets in bulk. To do this, they use monolithic rubber of hard or semi-hard grades. This material has a number of advantages:

  • insignificant gas and water permeability;
  • increased resistance to wear;
  • non-conductivity of electrical energy;
  • resistance to galling;
  • affordable price (especially when purchasing rubber gaskets in bulk).

The disadvantages of rubber products can be attributed only to their relatively short service life. As noted by the manufacturers, such rings can last for 1-2 years. This explains why the rubber seals cannot be reused. Thus, if, during the repair of the plumbing equipment, it is necessary to tighten the nut with such a ring, then it must be replaced, and the old product is thrown away. That is, a rubber ring is a standard consumable, so many repair companies and plumbers take such gaskets in bulk, not retail.

Note! Rubber sealing elements can be used in areas of the water supply system in which the pressure does not exceed 10 bar, and the temperature of the heating medium does not exceed 100 °C. If these values are exceeded, the sealing element will be damaged and lead to a loss of tightness of the connection.

The Masterprof company manufactures both standard gaskets from Russian-made rubber and high-quality gaskets with increased technical parameters from Italian-made rubber.

Silicone plumbing gaskets

Elastic silicone gaskets are versatile and have a wide operating temperature range. When installing them, do not use large torque forces. Silicone rings have almost the same technical and operational properties as their rubber counterparts, therefore, wholesale silicone gaskets are also very popular today. However, there are a number of differences between these types. Compared to rubber seals, silicone models have the following differences:

  • universality;
  • more expressed elasticity;
  • lack of the specific smell;
  • lack of sulfur in structure;
  • use in pipelines with the temperature up to 280 °C.
  • high price.

Considering the fact that the production of silicone gaskets in bulk is more expensive, some unscrupulous companies began to release PVC analogues on the market. In appearance, these materials are practically indistinguishable from each other. To ensure the quality, the product needs to be set on fire. Silicone does not burn, but smolders, unlike PVC, which immediately ignites.


Silicone seals are used in pipelines where the pressure does not exceed 10 bar and the temperature ranges from -50 to 280 °C.

Paronite plumbing gaskets

Paronite gaskets are used in gas and water supply systems with high pressure and temperature. Paronite sheet is a mixture of asbestos, rubber and some other components compressed under high pressure. Gaskets made of ordinary paronite can withstand pressures up to 64 bar and temperatures up to + 450 °C. Paronite gaskets are very resistant to sudden changes in pressure and temperature in the system.

There are 2 types of paronite seal rings:

  • reinforced - withstand working pressure up to 64 bar;
  • unreinforced - capable of withstanding a pressure not exceeding 40 bar.

Often, paronite gaskets in production and in other areas are used to ensure the tightness of flange connections. In everyday life, this material can be used to seal parts of a shower, divertor, mixer, etc.

MasterProf Company manufactures and sells wholesale paronite gaskets from two types of raw materials:

  • with asbestos content;
  • non-asbestos paronite.

Asbestos-free paronite is especially popular in the EU countries because it’s eco-friendly and safe for health.

Fluoroplastic plumbing gaskets

This is the rarest type of sealing materials. Its advantages include:

  • fire safety;
  • long service life;
  • environmental friendliness;
  • high level of elasticity;
  • resistance to the aggressive media.

However, the production of plumbing gaskets in bulk from this material is quite expensive, which explains the low popularity of such products.

PTFE plumbing rings can be used in areas of the plumbing system where the pressure does not exceed 110 bar, and the temperature ranges from -270-260 °C.

Fiber plumbing gaskets

Fiber gaskets are used to seal pipelines containing kerosene, gasoline, lubricant and oxygen. Fiber is a compressed paper pulp used as an insulating material impregnated with a special compound. These pads are considered disposable.

How to choose a plumbing gasket

In order to determine the material you need, use the following table. ‘++’ indicates the preferred application for each material.

Material / Application cold-water supply hot-water supply Gas Heating
Rubber ++ +
Paronite + + ++ +
Fluoroplastic + + + ++
+ ++
Fiber + +

Plumbing gasket sizes

Even professional plumbers often question the size of plumbing gaskets they need, and how to convert an inch to a metric scale. Although, it would seem that everything is so simple, you take a ½ "fitting, take a ½" gasket, connect and everything fits.

In fact, it is not that simple. There is no single standard for gaskets. The inch designation refers to the outer diameter of the gasket. Accordingly, we can use it to the inside-outside connection. But what if we plan to use this gasket on an external thread with a lock nut, which gasket to choose?

Plumbing gasket for external thread

In this case, we need to know not only the outer diameter of the gasket, but also the inner one. For these purposes, you can use the table of the exact sizes of the shims and their comparison with the inch sizes.

  Actual dimensions (outer diameter x inner diameter x thickness)
Product Size in inches Outer diameter, mm Inner diameter, mm Thickness, mm
Standard gaskets        
1/4 black gasket (for gauges) 1/4" 11 6 1,5
Gasket 3/8" 14 8 2
Gasket 1/2" 19 10 2
Gasket 3/4" 24 12 2
Gasket 1" 30 19 2
Gasket 1 1/4" 39 28 2
Gasket 1 1/2" 44 32 2
Special gaskets        
Radiator intersection gasket 1" 1" 41 32 1
Silicone gasket for plug and radiator adapter 1" 1" 39 31 3
Ring-stuffing box for 6x2.5 tap valve   10 6 2
Rubber oil seal for 8x12 tap valve   12,5 8 2,3
Ring for imported spout 12x19   18,5 11,5 2,3
Ring for imported spout 14(15)х19   18 14 2,3
EPDM nipple ring for 16 mm compression fittings   15 12 1,5
EPDM nipple ring for 20mm compression fittings   19 16 1,5
EPDM nipple ring for 26mm compression fittings   26 23 1,5
Helpful advice: Not all fittings can be used with plumbing gaskets. To determine, you need to look at the end of the thread of the fitting that will abut against the gasket. If it is flat, then no problem - you can use it. But if it is tapered, then, most likely, the fitting will cut the gasket and the connection will leak. In this case, it is better to use plumbing flax with paste.
Thread gasket

Plumbing washer dimensions

As a rule, new plumbing is sold with a set of all necessary gaskets. However, even in this situation, it is often necessary to additionally buy seals, for example, if there is a defect in the configuration, or the standard elements have already worn out. In this case, it must be borne in mind that the diameter of the purchased sealing washer should not differ from the diameter of a worn or defective washer. It is important to remember that it is not only the outer diameter of the gasket that matters, but also the inner diameter!

To indicate the size of the plumbing rings, special markings are applied to them or to their packaging, which makes it easier to choose a new product. Therefore, when repairing plumbing, you need to look in the manual for its operation and find a section in which the optimal diameter of the washer-seals is spelled out.

In the event that the instructions are lost, it is better to take the ring with you to the store so that the sales assistant can help you choose the right option. If there is no manual, no seal ring, or knowledge of the optimal diameter, then you can purchase a set of washer seals and choose the right product from it.

Wholesale plumbing gaskets

MasterProf Company is a manufacturer and wholesale supplier of plumbing gaskets for private plumbing stores, as well as large DIY stores. We use wide range of payment and delivery methods, as well as provide a detailed price list for the entire range of our products. The ordered plumbing gaskets in bulk are of high quality and are supplied in packaged form. Over the years, we have established partnerships with many stores and suppliers.

Our experts will help you organize your own business and select the suitable products.

Do you still have questions?
Call or e-mail us, we will answer.
Phone: +7 812 309-53-81