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cindyli@swdplastic.com +86-574-88324025

Plastic Diaphragm Valve

Size: DN15-DN100
Lead time: 30 days around
MOQ: 10ctns
Delivery: Ocean or Express
Port: Ningbo or Shanghai
Place of origin: China


Diaphragm valves working principle

Diaphragm valves have only three main components: body, diaphragm and bonnet assembly. The diaphragm separates the inner cavity of the lower valve body from the inner cavity of the upper valve cover, so that the valve stem, valve stem nut, valve disc, pneumatic control mechanism, electric control mechanism and other components located above the diaphragm are not in contact with the medium, and no medium will be generated. External leakage, eliminating the need for the sealing structure of the stuffing box.

Diaphragm valves structure

The sealing principle of the diaphragm valve is to press down the diaphragm or the diaphragm assembly and the valve body channel by the downward movement of the operating mechanism, so as to achieve sealing. The size of the sealing specific pressure is realized by the downward pressure of the closing part. Since the valve body can be lined with various soft materials, such as EPDM, PTFE or Teflon. Therefore, a complete sealing can be achieved with a small sealing force.

The diaphragm valve has a simple structure, small fluid resistance, and a larger flow capacity than other types of valves of the same specification; no leakage, and can be used for the adjustment of high viscosity and suspended particle media. The diaphragm isolates the medium from the upper cavity of the valve stem, so there is no leakage of the medium without packing. However, due to the limitation of diaphragm and lining materials, the pressure resistance and temperature resistance are poor, and it is generally only suitable for nominal pressure of 1.6MPa and below 150℃. Diaphragm valves have good anti-corrosion properties, so they are generally used in devices and pipelines for corrosive media. The valve body material is usually made of UPVC, CPVC, PPH, PVDF and other corrosion-resistant plastics.

Diaphragm valve has two connection methods: flanged  and union

Diaphragm valve structure diagram.png

1Cover limitAS
3Retaining NutStainlessSteel.
6PlatenAlloy material
7Double headed stud and NutSteel. StainlessSteel
8BonnetSteel. StainlessSteel
10StemHt300 Steel
11DiscSteel. StainlessSteel
12FlimFRPP. PVDF. UPVC. CPVC. PPH. Steel, StainlessSteel, C.I.FRP
13DiaphragmEPDM. FPM
14BodyF46 PFA

diaphragm valve Drawing.jpg


Working pressure and working temperature list



1. Our valves are fully inspected to ensure that they do not leak and feel right in the hand.                         

2. We send the same quantity of products free or send payment back once customers find a problem when getting goods.

3. We will reply to you within a workday and come up with solutions within 5 workdays when we receive your claim.

4. We will reply to you within a workday when receiving your inquiry.


1. What is your MOQ?   

Our MOQ is usually 10 CTNS.   

2. What is your delivery time?   

The time of delivery is around 30-45days.

3. What is the shipping port?   

ShanghaiNingbo、 XiamenShenzhenGuangzhou

4. What are your payment terms?  

We accept 30% T/T in advance,70% against the copy of  B/L, or 100% L/C.

5. How should I contact you?  

You can contact us with Trade Manager or send us an email by clicking Contact Supplier bottom.

6. What is the location of your company?

Our company is located in Ningbo, Zhejiang Province, China. If you would like to visit, you are much welcome.

7. How about the samples?  

We could send you the samples, most samples are free to send to most places in China. If sent to other countries, transport fee should be paid by you.

Our Services.png

1. Any inquiries will be replied to within 24 hours  

2.No leakage, pressure PN 10;  

3. Well and high-quality control ;  

4. Environment-friendly, non-toxic, good-looking, and long service life;

5. Lightweight, easy to handle and transport;

6. Soft colors and excellent design, suitable for installation either exposed or hidden;  

7. Wonderful ability in chemical corrosion resistance;  

1. Genuine products with excellent quality and competitive prices.

2. Cooperating with customers all over the world and knowing the markets very well.

3. We are a reputable company, the company has passed BV and SGS third-party certification.

4. After- Services will be highly-satisfied. Any problems and feedback will be answered in a short time.


Mob&Whatsapp: 0086 15869351645

Tel: 0086-574-88324025

Email: cindyli@swdplastic.com