Project Description

Rubber Check Valves

The Series 700 Rubber Check Valve is a cost effective way to control back pressures from sewage treatment plants, outfalls and tidal operations. They are a fully passive flow device requiring neither maintenance nor any outside sources of power or manual assistance to operate.
The Series 700  Rubber Check valves are offered as direct replacements for ineffective and maintenance ridden flap type rubber check valves, commonly known to seize, rust and bind in unwanted positions. Unlike flap type valves, the rubber check valve will handle large obstructions without jamming or having swing gates binding open. Specify the Series 700 rubber check valves to provide backflow protection from (1) Sewage slurries, (2) Outfalls to ocean fronts from heavy rainfall activity, (3) Prevention from land erosion due to back flow conditions, (4) Protection from saltwater to fresh water ponds and catch basins and numerous other water based applications. Our history in the manufacture of rubber piping products dates back to 1930. When an engineered solution is needed to solve a piping or backflow problem.
The Series 700 Rubber Check Valve are available in a Flanged (Style 710 or 720), Sleeved (Style 730 or 740), or Jacketed (Style 750).
Inline orifice (style 770/780)
Style 710: Flanged:
Designed to bolt directly to existing flanges or new installations, flanges are drilled 150# standard. Other drilling standards are also available upon request. The style 710 can be installed in either vertical or horizontal application.
Style 720: Flanged Inline:
Designed to fit directly inside of an existing pipe.
Supplied with a flat face rubber flange which allows installation between existing pipe flanges eliminating the requirement for a valve body. Other drilling standards are also available upon request.​
Style 730: Sleeve Type:
Designed to easily slip over an existing pipe, is affixed to a pipe with heavy-duty Stainless Steel clamps. Can be installed in either vertical or horizontal application.​
Style 740: Slip In Inline:
Designed to slip directly inside of an existing pipe. Supplied with a stainless steel expandable clamp to secure it in place.
Style 750: Jacketed:
Designed with a full metal enclosure which allows easy installation in existing piping systems. Utilizes the Style 710 as the rubber check valve.​
All of the Series 700 Rubber Check Valves are available in a various selection of elastomers including NSF/ANSI 61 certified material and back pressure capabilities to suit most applications.
The Series 700 Rubber Check Valves will not freeze or deform and functions solely on the inlet and back pressure which will be present in each application.
Each valve is carefully constructed using the finest of engineered materials and some of the most experienced rubber technicians in the industry. All rubber check valves are engineered in precise detail to ensure proper operation and will provide years of unhindered operation and trouble free service.
Benefits of the Series 700 Rubber Check Valves:
  • All rubber construction resists abrasive slurries
  • NSF61 is standard construction
  • Very quiet operation with no water hammer
  • Its unique design prevents backflow
  • Negligible maintenance and energy costs
  • Will not warp or freeze
  • Quick interchange with any flap type check valve
  • Available in sizes 1” – 96”
  • Available with special I.D to suit concrete pipe.
Frequently Asked Questions

Rubber Check Valve

1. Does the rubber check valve have to be installed in a certain position?
Yes; it should be installed in a vertical position with the bill being the vertical. In zero clearance situations the valve can be rotated up to 30 Degrees to gain bottom clearance if required..
2. In which degree can the rubber check valve be installed?
Because the valve is not reliant on any hinges, gates, or weights the rubber check valve can be installed in any angle from vertical to horizontal.
3. What is “Back Pressure”?
When the rubber check valve is submerged in a liquid it is subjected to external pressure. It is critical that the maximum depth that the valve will be submerged is specified as this will be considered the maximum back pressure that the valve will be subjected to.
4. What is the cracking pressure to allow the valve to open?
1”to 2” of water column over back pressure will normally drain a pipe.
5. What back pressures can the rubber check valve withstand?
Back pressures are in direct relation to the size of the valve, on the smaller diameters it is acceptable to specify up to 200 psi of back pressure and on larger diameters a back pressure limitation would be approximately 12 psi. Each rubber check valve is manufactured to the exact line pressure, back pressure and flow rates which we require from you for manufacture. We can even supply valves up to 650 psig utilizing internal back pressure supports.
6. What are the most common installations?
The 710 flanged rubber check valve is bolted directly to a head wall replacing an existing flap gate, the 730 sleeved type rubber check valves are clamped directly to a fabricated flanged nipple or clamped directly to an existing pipe.
7. Can I use the rubber check valve on potable water applications?
The rubber valves are available with an ANSI/NSF-61certified elastomer. Due to the large demand for clean water and potable applications, this will eliminate the concerns commonly affiliated with contaminants or leaching of elastomers in potable water systems.
8. Can the rubber check valve be installed on an “out of round” pipe?
Yes, please have the approximate dimensions from 4 different angles to provide proper sizing.
9. Can river currents and ocean waves damage the valves?
In most cases river currents and ocean waves will not damage the rubber check valves, but if currents or waves in question are of an abnormal nature, it is suggested that side walls or rock pilings are utilized.
10. Can the rubber check valve be used as a pressure relief valve?
No, the rubber valves have been designed to offer superior service as a back flow preventer and should not be considered for a pressure relief valve.
11. Can we make a special design to suit my requirements?
In most instances the rubber check valve can be fabricated to suit different applications.
12. What types of elastomer is available?
The rubber check valve can be manufactured and supplied to withstand almost any type of media. Most commonly supplied are Nitrile (nsf/ansi Standard 61 certified), Neoprene, Gum Rubber, Chlorobutyl and EPDM.
13. What types of materials are available for the backing rings and banding clamps?
rubber check valves are supplied with 316 stainless steel backing rings and 304 stainless steel clamps as a standard. Other materials are available upon request.
14. Can the 710 be supplied with special flanges or drilling?
Yes, the standard drilling pattern is ANSI 125/150# drilling, other drilling standards such as: ANSI 250/300#, BS-10, DIN NP-10 and DIN NP-16, JIS-5k and JIS-10K are available upon special request.
15. Can I install a rubber check valve near a residential area?
Yes, one of the unique features of the rubber valve is the design of the bill section. While the bill will open and allow passage of fluid when head pressure is present, the bill will close and not allow children or animals to crawl inside when there is no head pressure.
Since the rubber check valve is manufactured entirely of rubber compounds there is no chance of loud banging which is commonly heard from flap type valves.
16. Can I use a rubber check valve in winter conditions?
Yes, as in any installation the rubber valve will not be hindered by winter or sub-zero installations. If the valve is installed in a running water application the valve will continue to operate satisfactorily, due to the elastomers unique chemical makeup. If unusual circumstances occur the rubber valve will freeze without any damage and will return to operation upon thaw.
17. Will the rubber check valve operate if buried in sand or sediment?
In normal conditions the discharge flow will create a small flow pattern which will then be followed by the flow velocity of the media. This velocity will flush the rest of the sediment away from the valve opening. This has been found to be unique only to the straight bill design as supplied by Dannenbaum LLC.
18. What is the maximum temperature that the rubber check valve can handle?
Temperature can range from – 65 Deg to +400 Deg depending on the specified elastomer.
19. Is the rubber check valve suitable for direct sunlight and UV areas?
Yes, all rubber valves are manufactured with a highly resistant Nitrile external cover. In some applications the rubber check valve may be subjected to oil sludge’s which make Nitrile the perfect choice for protection.