Which thin walled stainless steel connection method is better???

Hello! I used to use thin-walled stainless steel pipes for a high-rise project, and I used a double clamping connection at that time! At that time, the design was preliminarily determined to be welded or pressed!

However, at that time, it was more inclined to weld the connection! Later, many manufacturers were selected, and an experiment was done on the spot during the bidding! Each manufacturer brought a model of the loop to suppress the experiment!

When the pipeline was added to 20 kg at that time, the inner silk rubber ring protruded, and the manufacturer did not agree to increase the pressure again, and the welded one also had obvious water seepage! At that time, there was a manufacturer that used a double pressure connection to continue pressurizing, and I remember that this manufacturer seemed to be Guangzhou Meiya at that time! When the pressure reaches 35 kg can not be under pressure is!

There is no water seepage deformation in the loop with double clamping! After our careful comparison and visit to the manufacturer, we are satisfied with the production technology of Guangzhou Meiya Company and the Japanese management method! Finally, the design was changed and the connection method of double press was adopted!

Personally, I feel that the double clamping is better! The construction is also more convenient! The pressure bearing capacity is better!

I hope my experience will help you!

Comparison of the advantages and disadvantages of commonly used thin-walled stainless steel pipe connection methods.

1. Mutual learning of stainless steel pipe standards at home and abroad.

The internationally used stainless steel pipe connection methods mainly include compression type (convex type), compression type, push type, welding type (socket argon arc welding type and butt welding type), etc., such as compression type and welded pipe wall thickness according to the British BS4127, EU DIN EN10312 standard, compression type (press type) using the Japanese JWWA G116 standard. Therefore, the domestic "wall stainless steel water pipe" standard, the wall thickness and other indicators of the stainless steel pipe are according to different connection methods, corresponding to the British, EU, ISO and Japanese standards.

2. Comparison and analysis of several connection methods.

1. Characteristics of convex type: easy to install, no deformation inside and outside the joint, belonging to the live joint, easy to maintain. Scope of application:

Cold water system, pipeline direct drinking water system, water treatment equipment system. Surface-mounted installation is more applicable, mainly considering the replacement of the sealing ring in the future, and the hot water system should be avoided as much as possible. The advantage of this connection is that the installation is simple, convenient, easy to maintain, and the sealing ring in the pipe needs to be replaced when it is aging, and it can be replaced as long as the nut is unscrewed.

The disadvantage is that the applicable occasion is single, the aging of the sealing ring in the hot water system is more prominent, and the cost is higher. Concealed pipes and hot water systems are generally not recommended.

2. Characteristics of press type: easy to install, the outer pipe of the connection and the internal rubber ring are evenly pressed into a hexagonal shape. Scope of application:

Cold water system, pipeline direct drinking water system, and surface-mounted pipeline are more applicable. The advantages are: simple and convenient connection, short working hours and moderate cost.

The disadvantage is that the applicable occasion is single, the maintenance is troublesome, and the sealing ring in the pipe needs to be replaced when it is aging, because it has been stuck when it is connected, and the replacement is necessary to cut off both ends of the pipe fittings before it can be replaced. The hot water system should also be avoided as much as possible, mainly because of the uncertainty of the service life of the sealing ring in the hot water system. Therefore, concealed pipes and hot water systems are generally not recommended.

What I know is that with resistance welding, (pressure welding), the weld seal is continuous, but overlapping.

Someone else used it to make a tank to store water.

There are four main connection methods for thin-walled stainless steel pipes:

1. Press-on connection -- divided into single press-and-double-press. Double clamping is the most stable connection. The radial contraction external force (hydraulic tong) is used to clamp the pipe fittings on the pipe, and the connection effect is achieved through the water stop of the O-ring sealing ring.

Easy to operate, good sealing, non-removable.

2. The expansion ring connection --- adopts radial contraction external force (hydraulic tong) to clamp the pipe fittings on the pipe, and through the water stop of the wide belt rubber sealing ring, the connection effect is achieved, and the pipe is installed to increase the process of rolling the convex ring at the end of the pipe; The tightness is average, and the cost of cast pipe fittings is high.

3. The welded connection --- adopts a hot melt process to weld the two connectors to achieve the effect of connection. The connection strength is high, and the weld gas protection of the on-site weld is difficult to meet the standard, resulting in easy rusting of the weld and directly reducing the service life of the pipeline; The installation quality is highly dependent on the technology of the welder, and the quality is difficult to stabilize.

4. Self-locking connection - the earliest used for small-diameter plastic hose connection, no need to use tools, quick installation. The inside of the interface is easy to loosen and leak, and the sealing is poor.

At present, there are four connection methods for stainless steel water pipes, welded type, threaded type, flange type, and crimp type, but now more of them are crimped type, and the common crimping type is clamping, double clamping and ring pressure, as well as a new type of double ring pressure and snap ring bonding type.

1. Single pressing: D-type pressing. The earliest thin-walled stainless steel crimping technology in China.

Features: O-ring (wire seal), hexagonal locking structure.

2. Double pressing: the improved S-type press-clamping connection technology on the basis of single pressing.

Features: Compared with the single-card port, the extension edge has been increased.

3. Ring pressure type: It is the improvement and development of the compression basis.

Features: The O-ring is changed to a wide band sealing ring (the elastic wire seal is changed to a filler seal), and the hexagonal deformation is changed to a ring locking structure, so that its sealing reliability and pressure-bearing capacity are improved.

1.Due to the use of filler seals, the ring pressure connection has low requirements for the matching accuracy of pipe fittings. Ring pressure stainless steel pipe fittings can adapt to pipes with larger tolerances, so there is little leakage due to small pipes in the ring pressure connection in practical applications.

2.After a long-term trial, the rated working pressure of GB33926 ring pressure stainless steel pipe fittings can be reached, which is the only product that can be used in the domestic extrusion connection method.

The two new types of connections are just perfect compression connections, with a wide range of connections, suitable for working environments from -50 to 150, and used for various pipe connections of caliber DN15-DN150.

Snap ring bonded.

Snap-ring bonded pipes combine mechanical and bonded connections. Give full play to the characteristics of anaerobic rubber, no longer rely on rubber ring sealing, make up for the shortcomings of the traditional clamping connection mode, use the thin-walled stainless steel pipe with adhesive connection, good circumferential rotation resistance, good sealing performance, high connection strength, simple construction, convenient operation, greatly save the cost of pipe and installation man-hours, is the most ideal way of stainless steel pipeline connection at present.

Double ring press-type connection.

Stainless steel water pipe "double ring pressure connection" method for the national patent product, is a new type of connection method, is on the basis of ring pressure pipe fittings to optimize the structure, increase the size of the sealing sleeve, on the basis of the original ring pressure to add two sealing surfaces, a total of 4 sealing surfaces, to avoid the sealing section of the hollow drum phenomenon, better sealing performance, to prevent leakage.

In the process of special tool pressing, the tool is along the outer edge of the stainless steel water pipe sealing section, and at the same time evenly extruded inward, according to the thickness of different rubber sealing snares, that is, the sealing bag, the scientific compression ratio is calculated to form at one time, so the tensile strength is high, the sealing performance is good, more scientific, more firm, and durable.

I know that there are clamping pressure, ring pressure, groove, flange, now with the clamping ring pressure more, I personally am more optimistic about the ring pressure, the ring pressure is the whole surface crimping, good sealing.

I used to use double ring pressure connection in the decoration of my home, which is not a public, but the effect is not bad, and the installation is also very convenient, I installed it myself.

1. Convex connection is currently the most advanced and competitive connection mode 2. Double clamping connection will slowly become the mainstream connection mode 3. Single clamping connection Many manufacturers are doing mainstream products but have been out 4. Welding has the largest tensile force But the requirements for construction and welding site protection are too high Slowly introduced to the market 5. Ring pressure Differentiated connection products But from the content of serious safety hazards has been listed Compare it yourself, of course, the lowest labor cost is of course the simpler construction of the product, Premise is that the security of the connection is guaranteed!

I have been engaged in related industries before, and it is convenient to press and ring pressure, but there are always some small defects, and it is the first time I have heard of card sticking, and it should be good to see the principle.

The traditional connection method of thin-walled stainless steel water pipe is clamping and ring pressure, but there are certain limitations and shortcomings, and the clamp ring bonding connection is the organic combination of mechanical and bonded two connection methods, giving full play to the maximum characteristics of anaerobic rubber, no longer relying on rubber ring sealing, making up for the shortcomings of the traditional clamping connection, with extremely high safety, reliability, aging resistance, corrosion resistance, long service life, its use temperature range has reached -50 to 150, more suitable for the use of extreme environments.

Stainless steel water pipe clamp ring bonding type connection, comprises connecting pipe fittings, adhesive layer and connected pipe, it is characterized in that, the inner wall of the pipe fitting of described connecting pipe fitting is coated with adhesive layer, the connected pipe is inserted into the connecting pipe fitting, and the overlapping part of connecting pipe fitting and connected pipe is clamped and molded to form a pressing section through a clamping die, so that the inner wall of the connecting pipe fitting is tightly bonded with the outer wall of the connected pipe through the adhesive layer. The press-fit section clamps out a plurality of arc grooves that are dislocated along the circumferential direction and arranged at axial intervals.

Stainless steel water pipe snap ring bonded connection, good circumferential rotation resistance, good sealing performance, high connection strength, simple construction and easy operation. It greatly saves the cost of pipes and installation man-hours, and is suitable for the connection of thin-walled stainless steel pipes in water supply systems and gas systems.

The anaerobic adhesive used in the stainless steel water pipe snap ring bonding type is a special anaerobic adhesive for stainless steel pipes provided by Loctite Company of the United States, which has been verified by the national professional testing and inspection agency. The aging resistance of anaerobic adhesive is far better than that of rubber materials, and it can play a role in bonding and non-seepage plugging in stainless steel pipe connections.

There is a new type of thread-to-lock connection method, which is also good.

Connected in this way, the locking structure and the sealing structure are separated. A machined silicone seal is used to connect the two ends of the pipe in combination with a straight-through. The connection is fast, no professional tools are required, only a wrench and a small hammer are needed.

In this sealed connection structure, the metal part bears the role of support and limiting, and the silica gel bears the sealing role, and the height of the silica gel after compression is the same as the height of the metal part, and the metal part strictly controls the compression amount of the sealing silica gel, so that the sealing silica gel is neither undercompressed nor too compressed, so that this sealing has an almost permanent service life.

I think the lock connection is better than other connection methods, no water leakage, durable, this is a patent, Ruijin stainless steel water pipe is a lock connection, there has never been a water leakage problem for decades.

Our unit used to use the connection method of clamping, but after a long time, some of the other party was a little leaky, I don't know if it was not good at that time.

Aren't metal water pipes all connected by welding and screws?

At present, the popular in the market is clamping and ring pressure, but the industry has developed, and other more scientific connection methods have appeared.

Thin-walled stainless steel pipes are mainly used in hot water from the material of the stainless steel itself, 304 stainless steel can withstand no more than 200mg liters of chloride ion content when it is lower than 40 (hereinafter referred to as cold water), but when the temperature exceeds 40 (hereinafter referred to as: hot water), the chloride ion resistance drops to no more than 50mg liters (Note:

The chloride ion content of urban tap water is 50mg liters) and with the rise of temperature, the chloride resistance is on a downward trend, and 316 (L) stainless steel is resistant to chloride ion content of 1000mg liters in cold water, and the chloride ion content in hot water can also be up to 250mg liters, so the most important thing is to consider the selection of materials, I think that 316 (L) thin-walled stainless steel pipes should be used in hot water. Don't be misled by the manufacturers for their own interests, the money is their own, the direction of the material is set, the rest is to save money is the king, which connection method is the most cost-effective to choose! [The material data mentioned in this article refer to 10s407-2 and 10s407-2 shall prevail].

1. Convex connection is currently the most advanced and competitive connection mode.

2. Double snap-on connection will gradually become the mainstream connection mode.

3. Single-card compression connection Many manufacturers are doing mainstream products but they are already out.

4. Welding has the largest tensile force, but the requirements for construction and welding site protection are too high, and it is slowly introduced to the market.

5. Ring pressure differentiated connection products but from serious safety hazards.

The content has been listed, so compare it yourself.

The lowest labor cost is, of course, the product with simpler construction, provided that the safety of the connection is guaranteed under the premise of comparison!