WaStop 230 Stainless steel

WaStop Inline Check Valve

Basement flooding
High Water Levels
Odor control
Protection from Animal Infestation
Pump stations
Surface water flooding
Tidal Water

WaStop inline check valves have been an industry leader since their inception in 2000.  Developed on the same principles that are the foundation of Wapro, WaStop’s ingenious function combines common sense and simplicity, to provide our customers with the best possible protection against flooding, odour control and backflow. 

  • Lowest headloss amongst inline check valves
  • Easy installation saving costs on contraction & installation
  • In-built automatic pulsating flow mechanism
WaStop 230 Stainless steel

Keeping common sense and simplicity as keywords throughout development, Wapro is able to provide a solution which can be installed in minutes in a wide range of pipes, with or without flanges, and at any angle. 

Wapro’s focus on simple innovative solutions has led to the development of our unique Memory Membrane.  Designed with the user in mind, this membrane ensures longevity.  We at Wapro understand that maintenance budgets are being cut back.  In tune with our customers’ needs, WaStop’s unique pulsating flow ensures that maintenance is kept to a minimum.  We also know that real life means our valves are put to the test daily with chemicals, temperature changes, debris and unforeseen events.  Our engineers work constantly with real life testing of existing and new materials to ensure our valves withstand real life environments.

We also understand that the ‘throwaway culture’ is being heavily criticized.  The value of ‘life-cycle cost’ over ‘cheapest possible purchase price’ has gained ground with a realization that during storm conditions, the function of the assets in the stormwater or sewer system is by far more important than the initial purchase price of the products in the system. 

In order to protect against flooding, we at Wapro have engineered the WaStop to ensure the lowest possible opening pressure whilst maintaining the best possible seal against backflow.  This, combined with the lowest headloss available, gives the most efficient flow conditions, ensuring the fastest evacuation of water.  An essential quality of check valves used to protect people and property.

Put WaStop to the test in your system to experience the Wapro difference.

We at Wapro know that any solution for flood prevention, or odor control needs to function. Simply, effectively. That’s why, when we invented the WaStop inline check valve in 2000 we had one thought in mind. Instant automatic protection. Working on differential pressure the WaStop functions autonomously, without human interaction, without electricity, without constant maintenance.

It just works.

To invent the best inline check valve on the market our engineers went one step further. We also thought about the different parts of the process and who would be affected by the design of the valve. With function top of mind our engineers developed a valve that works in stormwater, sewer, odor applications, as well as ensuring to cover the range of sizes of existing pipes to enable retro-fitting with ease.

We currently cover all sizes of pipes, all shapes and sizes, from 3-72". As standard. Off the shelf in most cases, for fast delivery. We keep stock to ensure the contractor and end user can keep time and costs to a minimum. We have a standard set of sizes which can be customized, quickly, to suit any application. Flanges on inlet, outlet or somewhere in between are all easily available. Quickly. Long life-cycle is part of our DNA. It’s part of our values. With this in mind we use the right materials for the right application. Stainless steel AISI 304 (EN1.4301) and AISI 316L (EN1.4404), along with a membrane material suited to the application.

The properties of the Memory Membrane:

  • Low opening pressure
  • Extremely low headloss
  • High resistance to external factors (temperature, chemicals, debris, abrasives)
  • Best possible seal against backflow in both high and low pressure events
  • Exceptional mechanical memory ensuring longevity
  • In-built, automatic, pulsating flow action

We at Wapro know that there is a wide range of pipes available on the market, and that these pipes aren’t always perfect.

To ensure the valve we provide you with fits perfectly and protects 100% we’re engineered the guess work out of it. Keeping in line with our customer promise of common sense and simplicity, we have developed a standard range of WaStop from 3-72". On top of this we have a Superior Fit Seal to ensure there is no leakage between the existing pipe and the WaStop Inline Check Valve.

We designed this seal to not only create the perfect fit, but also to ensure quick easy installation. Time is money.

For the residential market we have designed a range of valves for protecting memories. Protecting basements filled with photographs, toys, electronics or books can be easily done with a PVC/PE WaStop Inline Check Valve.   Click here to read more about these valves.  

WaStop Dimension Drawing

Stainless Steel Models

  NPS L L-Short OD Seal OD Body OD waist (/sh) Opening pressure standard Closing pressure standard Weight Shop Drawing (PDF) Shop Drawing (DWG) Technical Specification
  [inch] [inch] [inch] [inch] [inch] [inch] [inH2O] [inH2O] [lb]      
WS97 4 8,3 6,3 4,0 3,8 3,7 7 3 1,5 PDF icon ws97-s-us.pdf Binary Data ws97-55-304-us.dwg PDF icon ws97_nps_4in.pdf
WS101 4 8,5 6,5 4,1 3,9 3,8 7 2 1,8 PDF icon ws101-s-us.pdf Binary Data ws101-55-304_us.dwg PDF icon ws101-sh_nps_4in.pdf
WS116 5 9,1 6,3 4,7 4,5 4,4 10 4 2,0 PDF icon ws116-s-us.pdf Binary Data ws116-55-304-us.dwg PDF icon ws116_nps_5in.pdf
WS146 6 11,8 7,9 6,3 5,7 5,5 9 3 5,2 PDF icon ws146-s_us.pdf Binary Data ws146-55-304-us.dwg PDF icon ws146_nps_6in.pdf
WS183 8 15,2 10,6 7,9 7,1 6,8 10 5 9,3 PDF icon ws183-s-us.pdf Binary Data ws183-55-304_us.dwg PDF icon ws183_nps_8in.pdf
WS193 8 15,6 10,8 8,3 7,5 7,2 8 4 10 PDF icon ws193-s-us.pdf Binary Data ws193-55-304_us.dwg PDF icon ws193_nps_8in.pdf
WS215 9 17,7 11,8 9,3 8,5 8,1 9 5 12 PDF icon ws215-s_-us.pdf Binary Data ws215-55-304_us.dwg PDF icon ws215_nps_9in.pdf
WS230 10 18,9 12,6 9,8 9,1 8,7 8 5 14 PDF icon ws230-s.pdf Binary Data ws230-55-304-us.dwg PDF icon ws230_nps_10in.pdf
WS240 10 20,5 13,8 10,2 9,4 9,1 7 4 15 PDF icon ws240-s-us.pdf Binary Data ws240-55-304-us.dwg PDF icon ws240_nps_10in.pdf
WS283 12 23,6 15,7 11,9 11,1 10,8 9 4 22 PDF icon ws283-s-us.pdf Binary Data ws283-55-304-us.dwg PDF icon ws283_nps_12in.pdf
WS290 12 23,6 15,7 12,2 11,4 11,0 9 6 22 PDF icon ws290-s-us.pdf Binary Data ws290-55-304_us.dwg PDF icon ws290_nps_12in.pdf
WS340 14 27,6 19,7 13,9 13,4 12,9 14 9 40 PDF icon ws340-s-us.pdf Binary Data ws340-55-304-us.dwg PDF icon ws340_nps_14in.pdf
WS370 15 28,7 19,7 15,5 14,6 14,1 9 6 44 PDF icon ws370-s-us.pdf Binary Data ws370-55-304_us.dwg PDF icon ws370_nps_15in.pdf
WS390 16 29,5 19,7 16,3 15,4 14,9 12 7 53 PDF icon ws390-s-us.pdf Binary Data ws390-55-304-us.dwg PDF icon ws390_nps_16in.pdf
WS440 18 33,1 22,0 18,4 17,4 17,0 8 6 62 PDF icon ws440-s-us.pdf Binary Data ws440-65-304_us.dwg PDF icon ws440_nps_18in.pdf
WS490 20 35,4 23,6 19,9 19,3 18,7 11 7 64 PDF icon ws490-s-us.pdf Binary Data ws490-65-304_us.dwg PDF icon ws490_nps_20in.pdf
WS590 24 47,2 31,5 23,7 23,1 22,3 15 9 106 PDF icon ws590-s-us.pdf Binary Data ws590-65-304-us.dwg PDF icon ws590_nps_24in.pdf
WS690 28 51,2 34,3 28,0 27,2 26,4 11 7 139 PDF icon ws690-s-us.pdf Binary Data ws690-65-304_us.dwg PDF icon ws690_nps_28in.pdf
WS750 30 55,1 37,4 30,3 29,5 28,6 15 9 165 PDF icon ws750-s-us.pdf Binary Data ws750-65-304_us.dwg PDF icon ws750_nps_30in.pdf
WS790 32 59,1 39,4 31,9 31,1 30,2 14 9 194 PDF icon ws790-s-us.pdf Binary Data ws790-65-304_us.dwg PDF icon ws790_nps_32in.pdf
WS885 36 66,9 - 36,0 34,8 33,7 16 11 256 PDF icon ws885-s-us.pdf Binary Data ws885-65-304-us.dwg PDF icon ws885_nps_36in.pdf
WS985 42 70,9 - 40,0 38,8 37,6 15 10 311 PDF icon ws985-s-us.pdf Binary Data ws985-65-304_us.dwg PDF icon ws985_nps_40in.pdf
WS1050 42 76,8   47,8 41,4   17 11   PDF icon ws1050-85-304-fl.pdf   PDF icon ws1050-std_us.pdf
WS1185 48 88,6 - - 46,7 45,5 18 11 639 PDF icon ws1185-s-fl-us.pdf Binary Data ws1185-75-304_us.dwg PDF icon ws1185_nps_48in.pdf
WS1385 56 102,4 - - 54,5 53,1 21 14 970 PDF icon ws1385-s-fl-us.pdf Binary Data ws1385-75-304_us.dwg PDF icon ws1385-fl_nps_56in.pdf
WS1485 60 110,2 - - 58,5 56,7 24 15 1415 PDF icon ws1485-s-fl-us.pdf Binary Data ws1485-75-304-fl_us.dwg PDF icon ws1485-fl_nps_60in.pdf
WS1585 64 118,1 - - 62,4 60,7 24 15 1543 PDF icon ws1585-s-fl_us.pdf Binary Data ws1585-75-304-fl_us.dwg PDF icon ws1585-fl_nps_64in.pdf
WS1785 72 122,0 - - 70,3 - 26 17 2028 PDF icon ws1785-s-fl_us.pdf Binary Data ws1785-80-304-fl_us.dwg PDF icon ws1785-fl_nps_72in.pdf


PE Models


We at Wapro believe in enabling. By being an open organization we learn from, and share with, our customers. Below you’ll find that there is a wealth of information in relation to not only our products, but also other useful and interesting information to help you in your role. If you require any further information please don't hesitate call us. We’re here to help you stop flooding.

Technical Documentation

Technical drawings and specifications can be downloaded for each dimension under the tab for Dimensions and Technical Drawings.  Below you'll find information relating to WaStop such as installation instructions and White Papers.  Please contact us if you require any other information.

Certifications and Approvals

A rigorous testing procedure is undertaken at Wapro to ensure our valves meet our exacting standards.  Our valves tested to appropriate standards in our target markets at third party organizations such as Utah State University Hydraulics Lab and with Kiwa on an annual basis.  

CE-approved models (NPS 3-8") are tested according to SS-EN-13564. Other dimensions are tested according to the same standard. WaStop is patented in the EU, USA and other countries.

WaStop is extremely adaptable in regards to installation options. It can be installed from horizontal to vertical and in both cases can be installed for use in both directions. Joint connections are available for purchase upon request.

Common installations include:

  • Inlets and outlets
  • Installation in an existing pipe
  • Pump stations
  • In manholes and chambers

A rigorous testing procedure is undertaken at Wapro to ensure our valves meet our exacting standards. Our valves tested to appropriate standards in our target markets at third party organizations such as Utah State University Hydraulics Lab, Danish Technological Institute.  Kiwa Sverige AB on an annual basis.

CE-approved models type 0 (NPS 3-8") are tested according to SS-EN 13564-2:2002.
WaStop also meets the requirements according SS-EN 13564-1:2002 and quality assurance according SS-EN 13564-3:2004. Other dimensions are tested according to the same standard and meets the same requirements and quality assurance.

WaStop is patented in the EU, USA and other countries.