Stainless steel pipes have a long history in the world, with early thick-walled threaded connections and welded joints. Due to the high cost of thick-walled stainless steel pipes, although they are sanitary and superior in performance, they do not fully comply with the social development concept of energy conservation.

Therefore, some experts have studied the technology of “thin wall” connection of stainless steel. In the late 1950s, Swedish engineer Gunnar Larsson invented the press-fit connection technology. In 1969, Mapress, Germany, began production and sales of press fittings, mainly carbon steel systems (water pipes, fittings, rubber rings, tools). In 1984, Mapress produces stainless steel press fittings systems (outer diameter 15-50.0mm). In 1993, Mapress produces large-size stainless steel systems (outer diameter 76.1-108.0mm). Since then, the press-fitting system has been widely used all over the world (such as the United Kingdom, Italy, Japan, South Korea, Australia, Singapore, etc.), and the press-fit connection has become one of the standard methods of pipe connection.

GD Press fitting is made of 316L stainless steel. Stainless steel materials have outstanding corrosion resistance and good mechanical properties, and can be made into thin-walled tubes to reduce costs. The continuous development of thin-walled stainless steel water pipe connection technology ensures the technical performance required for water supply and drainage design, and overcomes the high price of thick-walled stainless steel pipe and the instability of threaded connection. The natural development of market demand and the promotion of the application of thin-walled stainless steel water pipes are inevitable. Therefore, many countries have promoted the use of thin-walled stainless steel pipe systems in various industries. Thin-walled stainless steel pipes, due to their small wall thickness, are generally not suitable for threaded connections. Stainless steel press fittings have the advantages of quick and easy installation, stable pressure resistance, corrosion resistance, and no pollution to fluid media. They are perfect joints for thin-walled stainless steel pipes. Press fittings are divided into M profile and V profile.

Here are 6 advantages of SS press fittings you want to know.

#1 Easy and quick installation

A special rubber sealing ring is installed in the U-shaped groove at the end of the stainless steel press fitting. When installing, the stainless steel water pipe is inserted into the press-fit port of the stainless steel press fitting to the positioning step position, and the special clamping tool is used for the U-shaped groove and U. The pressing portion on one side or both sides of the groove is simultaneously pressed. The rubber sealing ring is sealed after being pressed, and the stainless steel press fittings and the stainless steel water pipe are simultaneously contracted and deformed at the pressing portion (the cross section forms a hexagonal shape), and the positioning and fixing function is realized, thereby effectively connecting the stainless steel pipe fittings. It is suitable for low-pressure fluid transportation of cold water, direct drinking water, heating, air conditioning, fire fighting, gas and other civil low-pressure fluids. It can also be used for low-pressure fluid transportation in medicine, beverage, food, chemical and other industries.

Avoid on-site welding and threading operations. Field welding of pipe fittings or threading operation is laborious, water leakage rate is high, environmental pollution is easy to cause risks. Installation of press fittings is very convenient. Installation time is only 1/3 of that of welded pipe fittings or sleeve pipe fittings, which shortens the construction period, reduces the cost, avoids leakage and reduces the risk. ABS pipes are bonded by ABS sol, while cast iron pipes are usually bonded by wire, which is easy to leak. Other stainless steel pipes are welded, which has high cost and long construction time.

Besides, everyone can install press fittings, you don’t need to hire an expensive technical installer and you can do it yourself. Save a lot of time, material and financial resources.

#2 Safety and reliable

The press fittings have high connection strength and anti-vibration. The connection part is “dead” once, which avoids the possibility of loosening the “loose joint”, such as house vibration, water hammer vibration, pipeline resonance, and loosening caused by earthquake.

Different sizes lead to different working pressure. And the max working pressure is up to 40 bar. For example,

Size Max working pressure
OD15-OD28 40 bar
OD35-OD54 25 bar
OD76.1-OD108 16 bar

Defferent materials O-rings lead to different working temperature. For example,

Material Color Working temperature Application
EPDM Black -20°TO 120° Potable water, cooling system, etc
FKM Green -20°TO 200° High temperature system, Solar, etc
HNBR Yellow -20°TO 100° Oil, gas, lubricants, etc

The coefficient of thermal expansion of stainless steel press fitting is 1/4 of that of other plastic products. Excessively high expansion coefficients can cause water pipes to leak when the ambient temperature changes.

The tensile strength of stainless steel press fittings is ≥ 530. The tensile strength of the plastic is ≥ 49, and the tensile strength of the plastic is only 9.2% of that of stainless steel. Insufficient strength is one of the factors that cause water pipes to leak due to external forces.

Long lasting. Under the prescribed long-term continuous working pressure, the service life of cast iron pipes can reach more than 100 years. The corrosion and rusting of cast iron pipes are easy, the service life is short and the PPR is less than 1/4 of that of stainless steel.


#3 Health and Environmental protection

Press fittings are made 316 stainless steel. The sealing ring is made of EPDM, FKM or HNBR. It has good hygienic and environmental performance and long service life. Stainless steel is recognized as the healthiest material in the world and can be implanted in the human body. It is not easy to rust, acid, alkali, salt and corrosion. In daily life, we can often see tableware made of stainless steel. Such as stainless steel knives, forks, plates, etc. More important, stainless steel press fittings can be recycled 100%. ABS and PPR pipes can not.

EPDM rubber has Excellent aging resistance, weather resistance, ozone resistance, sunlight resistance, heat resistance, water resistance, water vapor resistance, UV resistance, radiation resistance, etc.And Excellent chemical resistance, acid, alkali, detergent, animal and vegetable oil, alcohol, ketone, etc.; outstanding water resistance, superheat resistance, water vapor resistance; resistance to polar oil.

FKM (ISO called FPM) is a fluororubber-based elastomer with excellent heat resistance, weather resistance and resistance to many other chemicals.

HNBR (Hydrogenated nitrile rubber) is a highly saturated elastomer obtained by special hydrotreating of nitrile rubber. Hydrogenated nitrile rubber has good oil resistance (good resistance to fuel oil, lubricating oil, aromatic solvent); and due to its highly saturated structure, it has good heat resistance and excellent chemical resistance. Freon, acid, alkali have good resistance), excellent ozone resistance, high compression set resistance; hydrogenated nitrile rubber also has high strength, high tear performance and excellent wear resistance. It is one of the most comprehensive rubbers.


#4 Low cost of labour

No welding, threading or rolling work, so professional installer is unnecessary. Everybody is able to do it. Maintenance-free, renewal-free, superior economic performance: in the life of the building, it is almost unnecessary to update and maintain the press fittings, which saves a lot of environmental renewal costs, and tends to zero customer property loss and service loss.

In developed countries, for example Europe and America, labor costs are very high. The feature that everyone can install makes the manual installation cost of the stainless steel press fittings greatly reduced. Due to its long design life, it can be maintenance-free even later. This greatly reduces the cost of post-maintenance.

#5 Low flow pressure loss

Flow rate refers to the amount of fluid flowing through a closed section or an effective section of an open channel per unit time, also known as instantaneous flow. When the amount of fluid is expressed in terms of volume, it is called volume flow; when the amount of fluid is expressed in mass, it is called mass flow. The volume of fluid flowing through a section of tubing per unit time is referred to as the volumetric flow of the cross section.

The inner diameter of the press fitting is the same as the inner diameter of the pipe (equal diameter design), and the deformation of the pipe at the pressing part is small, so that the flow and pressure loss at the pipe joint are small and negligible.

Principle of press fittings:

  • Pull-out principle: the middle position of the snap-in pipe fitting is small, but the two ends are large, and the pull-out is >3.0mpa.
  • Leak-proof principle: the U-shaped groove is filled with O-ring seals to shrink radially and hold tightly, leaking water, instead of leaking water.
  • Anti-rotation principle: The special card pressing tool presses the card into a hexagon to prevent the water from leaking during use.


#6 Wide range of applications

It is suitable for low-pressure fluid transportation of cold water, direct drinking water(for example residential, office, airport, railway station and other buildings), heating, air conditioning, fire fighting, gas and other civil low-pressure fluids. It can also be used for low-pressure fluid transportation in medicine, beverage, food, chemical and other industries.GD press fittings are available in a wide variety of specifications, and can be used with various valves, faucets, water meters, pumps, etc., and can be connected with various existing piping systems. GD press fittings system has a beautiful appearance, can be installed to improve the decorative effect, and can also be concealed to meet the requirements of embedded installation technology.

Last, the construction precautions for stainless steel press fittings

Stainless steel press fittings are thin-walled stainless steel pipe fittings. Please avoid rough operation to avoid sag and dents, especially at the site, be careful not to trample the pipe fittings.

The storage of pipes, try to avoid direct sunlight, please use plastic belt or security cloth to cover protection.

When the stainless steel press fitting is stained with oil, be sure to insert it clean. In particular, the end of the pipe and the rubber seal of the pipe fittings determine whether there is any foreign matter. If there is any foreign matter, it should be disposed of immediately to avoid more serious consequences.

If the pipe fitting cannot be inserted smoothly into the pipe, check whether the burr of the pipe port has been removed, especially the burr on the inner wall. The burr will directly affect the joint between the pipe and the pipe.

After the stainless steel press fitting is inserted, it will not be pressed temporarily. It is necessary to first tighten the thread and then press it to prevent the clamped joint from loosening due to the rotating thread.

When the piping is not bent correctly, please correct it in the straight pipe. Do not correct the pipe parts, and the card pressure may be loose, which is also the cause of the leakage. Please pay attention.

If there is slack in the pressure of the card, you can press it again at the original pressure (note the direction of the hexagon).

When the pipeline system is used for other media other than water (such as oil, chemical, gas, etc.), please contact the manufacturer to discuss that the rubber seal may be damaged by the corrosion of the medium and may cause leakage.

The pipeline system should consider anti-corrosion measures when it is used near the coast or in a place with a lot of salt water. In addition, it should be paid attention to when using well water, sea water, hot spring water, and fluids with high salt content.

When using water for hot water, if the water source is untreated well water, consider whether it will have adverse effects on the piping. Please pay full attention.

GD press fittings is approved by DVGW, OVGW, WRAS, SVGW, WaterMark, VA and so on. It is made by Grande-Tek Flow Control Co., Ltd . As a stainless steel press fitting manufacturer and exporter with more than 20-year history in this line. Grande-Tek attends many exhibitions every year. For example ISH, MCE, Stainless steel World and Carton Fair. Welcome to visit us anytime.