How to design the standard PVC pipe fittings?

With the development of social economy, lightweight, durable, multi-functional PVC pipe material has been more and more widely used. We now use all kinds of PVC pipe fittings in our homes and yards. It is a common mode of transportation for hot and cold drinking water, sewage and drainage systems. However, only with PVC pipe joint connection, in order to play a greater role. Thus, what is the standard of the PVC pipe fittings? How can we design the PVC pipe coupling which meet the criterion? I will tell you some thing about it in this article.

• What is the standard PVC pipe joints?

• The design ideas of the PVC pipe coupling

• What materials should we use during the design of the PVC pipe fittings?

What is the standard PVC pipe joints?

Only standard PVC pipe fittings can be used, and more and more people will be willing to use it. Standard means high quality. There are three main criterias as follows.

1.      The raw material for the production of PVC pipe joints is a mixture of hard PVC, which should be based on PVC resin and produce the necessary additives to meet the following requirements which part should be added. The quality percentage of polyvinyl chloride (PVC) resin in PVC pipe coupling is preferably above 85%.

2.      PVC pipe joints shall be intact and the inside and outside walls of the pipe shall be smooth without bubbles, cracks and obvious marks, dents, uneven color and discoloration.

3.      The wall thickness of PVC pipe fittings should meet the corresponding regulations. In the case of core excursion, the wall thickness of the thinnest part of the pipe is allowed to be reduced by 5% from the corresponding specified value.

The design ideas of the PVC pipe coupling

PVC pipe fittings have many restrictions. For example, the processing stability of PVC pipe joints is not good, the melting temperature (160 ° C) is higher than the decomposition temperature (140 ° C), the melt viscosity is high, and the fluidity is poor. Even with the increase of injection pressure and melt temperature, the change of fluidity is still small. Because the molding temperature of the PVC pipe coupling is very close to the thermal decomposition temperature, and the temperature range for forming is narrow, it is very difficult to form. There are two commonly-used methods. One of the modification methods is to add stabilizer in the manufacturing process of PVC pipe fittings to increase the decomposition temperature to higher than the melting temperature. The second method is to add plasticizer to reduce the melting temperature of PVC pipe fittings below the decomposition temperature.

What materials should we use during the design of the PVC pipe fittings?

The following is the information about the materials we should use during the design of the PVC pipe joints.

1.      Stabilizer: The Principle of stabilizer: base lead salt inhibits its autocatalytic activity by capturing the separated hydrogen chloride.

2.      Plasticizer: DOP dioctyl phthalate is used as plasticizer for PVC pipe fittings. It has good compatibility, good light stability and good electrical insulation.

3.      Lubricant: Metal soap is a kind of metal salt of higher fatty acid, which is one of the commonly used lubricants. In addition to lubrication, it is also a heat stabilizer for PVC pipe coupling.

4.      Modifier: ACR is an acrylate copolymer with core-shell structure, which is an impact modifier of PVC with excellent comprehensive properties.

This article deals with the problem that how to design the standard PVC pipe fittings. I believe you will know more about the PVC pipe joints after reading this paper.