What is Sanitary Diaphragm Valve
Connection mode classification of sanitary diaphragm valve:
There are three mode of connections of sanitary diaphragm valve, which are lap joint flange, fast connection and welded connection.
Welded connection divided into welded connection type I ( both ends of welding), welded connection type II (one end of the welding, the other end of the insert).
The features of sanitary diaphragm valve:
- The opening and closing elastic seal of sanitary diaphragm valve, body sealing adopts structure of arc design, to ensure there is no inside leakage.
- A streamlined flow channel, to decreases resistance.
- Body and cover is separated by intermediate diaphragm, to ensure the bonnet and the stem above the diaphragm won’t get eroded by medium.
- Diaphragm is replaceable, the cost of maintenance is low.
- The place at eye sight can show the state of switch.
- Advanced polishing process insures be sanitary, without dead angle and residue.
- Compact construction is suitable for valve installation with small space.
- Diaphragm can meet the security standards for pharmaceutical and food industry with FDA and UPS.
The structure of advantage of sanitary diaphragm valve
The flow of sanitary diaphragm valve is large, the body of valve has large space to ensure free discharge, in the middle of the diaphragm is independent, was made up by suitable materials, the maintenance cost is low, can meet the need of online cleaning and sterilization.
The structure of the sanitary diaphragm valve as the picture shows. The opening and closing part is a piece of diaphragm of the valve.
In a pharmaceutical water system, this diaphragm should be clean, non-toxic, no separation material, and won’t fall off, can meet the requirements of drug management administration(such as FDA, SDA and so on), this diaphragm is between the body and the bonnet.
The highlights of the middle of the diaphragm was fixed on the valve stem. The process water can’t into the lumen of the valve cover, so the health level of sanitary diaphragm valve is highest.
The advantages of sanitary diaphragm valve: simple structure, good sealing, easy to repair, small fluid resistance. The principle of action as the picture.
Special Design of sanitary diaphragm valve for Pharmaceutical water system
Pharmaceutical water system and manufacture design of sanitary diaphragm valve has some special properties, such as:
?Inside and outside of the valve surface is smooth(graphic), the light sell degree is about 1.6~0.25?m, the valve is easy to be completely cleaned.
?There is a proper angle of the body design, can residual all the water in the body.( graphic)
?The consistency of the diaphragm and the sealing are good, especially it has good flexing resistance, long operating life, no leakage, good hygienic of the diaphragm, no precipitation and no pollution for long time using, can tolerate steam sterilization for high temperature processing.
?Sanitary diaphragm valve is manufactured by steel forging with 316L, it can meet the requirement of high degree of finishing. And the forge piece has good welding ability, this manufacturing process is a strong support for badge biological control.
?Easy to repair, not easy to be polluted.
To sum up, sanitary diaphragm valve is made up by body, valve cover and diaphragm plate. The material of valve should be anti corrosion, so we adopt 316L and do track investigation for these valves. Welding documents required to be clear of the body material.
Diaphragm plate materials should be compatible with the process liquid and approved by the drug administration department, must be consistent with health treatment. The materials of sealing rings are TFE or PTFE gasket, they can anti heat. Elastic diaphragm has composite layer design, most of them adopt EPDM. High purity fluid using PTFE, the pad used EPDM gasket, the connection for both should be suitable for online sterilization.
Other diaphragm material must be checked carefully and sanitization method of adaptability, to ensure that they won’t bring other substances in the water. The key is to realize the diaphragm material can’t be lively, don’t add any material or can’t be absorbed by water, so you can avoid the change of the safety of drug, characteristics, strength, quality, or purity due to the influence of the material of diaphragm.
When the material we selected can meet the requirements, we must consider the process of sanitization.
Comparing with the forging body, iron content of sanitary diaphragm valve is low(<0.5%), good corrosion resistance, no pores on the surface after forging, can form a better surface finish, especially after electrolytic polishing, the surface roughness can reach a high level. The biggest disadvantage is the cost of sanitary diaphragm valve is high.
*The article was collected and revised by WELLGREEN PROCESS SOLUTIONS– Your reliable solutions of sanitary valves and fittings .