作者： wisnex@aliyun.com

Check valve is two-port valve, meaning it has two openings in the body, one for fluid to enter and the other for fluid to leave. Check valve, also be called non-return valve or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. There are various types of check valves used in a wide variety of applications. In household RO water purify system, check valve is a small but important component.

The role of check valve in RO water purifier:

Check valve, also known as non-return valve, back pressure valve, one-way valve. This kind of valve is automatically opened and closed by the force generated by the flow of pipeline mediation itself, it is a kind of automatic valve. Used in household RO water purifiers, between RO membrane outlet and pure water pressure barrel (water tank), it is RO membrane pure water fitting. The pure water produced by RO membrane can flow only from RO membrane to water tank, and can’t flow back, the water purifier stops working when water tank is full. The check valve is located in the pure water outlet of RO membrane vessel, is the first component that pure water contacts after being produced, its role is to prevent backflow of the pure water from leading to waste of resources.

Check valves work automatically and most are not controlled by a person or any external control; accordingly, most do not have any valve handle or stem. An important concept in check valves is the cracking pressure which is the minimum upstream pressure at which the valve will operate.

To resolve the issues of low upstream pressure at some areas, WISNEX invented and developed the models of LARGE FLOW check valve, with the patent for invention No.2013100385724, 2013200559539.  We can manufacture this kind of LARGE FLOW straight check valve,  elbow check valve. Through our extensive testing, It has good performance even at low water pressure situation.

Feed water pressure and outflow comparison table:

Features Of WISNEX LARGE FLOW Check Valve

• Low cracking pressure requirement (high sensitivity)
• Large water flow
• Not easy to block
• Good abrasion resistance
• Good sealing
• Long working life

Quick water filter connection fittings (push in fittings) are transportation hubs for water purifiers, including UF water filters, RO water filters. The quick fittings quality (sealing, pressure bearing capacity, durability), is an important factor affecting water purifiers. All good water purifiers are equipped with reliable quick fittings. So, what are the main factors that affects the quality of quick fittings? Here are some aspects that you may pay attention to when choose quick fittings for the installation of your water filters.

1. Seal o-ring of water filter connection fittings

1)  single or double

If the probability of damage / failure of single o-ring is 0.1%, then the problem for the double o-rings is just 1ppm (one millionth)

2)  Unfixed or fixed

The unfixed o-ring(s) will move and then maybe deform or damage during using, the off-center position or damaged o-rings will cause seal failure and leakage.

The fixed o-ring(s) can ensure the sealing effect and avoid leakage effectively.

Wisnex water filter fittings 5/16” and 3/8” series are all equipped with double fixed o-rings, which successfully pass 100,000 times of destructive fatigue test @10-12bar and stress test @30bar,with ZERO leaking.

2. Structure of water filter connection fittings

The traditional quick connectors are produced through welding process (the small cap is welded to the main body at the push in side), during which there are occasionally missing weld, incomplete weld and burr, and some of them are not easy to be detected in test process,they would bring leakage after a period of using.

WISNWX Aqua Fittings patented bite type structure is purely jointed by the concave-convex design in cap and main body, so as to effectively avoid those weld problems, and also significantly increase the pressure (up to 30 bar) that the fittings can stand at long term using.

3. Claws of water filter connection fittings

The inner claw of the quick connector requires a certain movable space, when inserting the PE tubes into the quick connectors, claws are able to move a little along with the tubes , and thus grip the tube more firmly.

Too tight claw is likely to cause the pipe to fall out during using.

WISNEX Aqua Fittings are all designed with repeatedly tested data, which make the connection very easy and comfortable, and the most important-safe.

WISNEX quick connectors are manufactured from safe, non-toxic POM, meeting the requirements of US FDA, NSF, WQA and WRAS. Our products are widely used in water treatment industry, beverage/food process, gardening/irrigation, and auto tubing etc., that including liquids, air, vacuum and gases connections etc.

For new customer with regular quick connectors

1. Inquiry (by customer)
With detailed demand info: item description with type/size (tube OD&thread info), quantity

2. Quote within 12 hrs (by WISNEX)

3. Check the price and place a sample order/trial order (with PO) (by customer)

4. Send PI (by WISNEX)

5. Arrange the (down)payment according to PI (by customer)

6. Arrange the production (or packing directly if there is in stock) (by WISNEX)

If the 5) is down payment, then there is 7) finish the balance after the packing (by customer)

8. send out by air express/air/sea (by WISNEX)

For new customer with special product(s)-need to make moulds

1. Inquiry
With detailed demand info: picture(s)/drawing(s), with some description for the product and the using area.

If the drawings are clear enough to develop molds(s),

2.  Quote the molds cost within 24hrs (by WISNEX)

3.  Check the price and place an order to make mold(s) (with PO)(by customer)

4. Send PI (by WISNEX)

5. Arrange the down payment according to PI (by customer)

6. Arrange the mold(s) development and samples production after the molds making (by WISNEX)

7. Send the samples to customer’s test by air express (by WISNEX)

8. Do test of the samples and feedback to WISNEX (by customer)

If the samples are approved by customer

1. Place the trial order (by customer)

2. Send the PI (by WISNEX)

3. Arrange the payment of balance of mold(s) cost and the payment of products (by customer)

4. Arrange the production (by WISNEX)

5. Send out the products by air express/air/sea (by WISNEX)