PTFE Diaphragm
Relief, By-Pass, Anti-Siphon and Back Pressure Valves...
for Smooth, Sensitive Operation and the Ultimate in Corrosion Resistance
...with No Wetted Elastomers or Metals!
FEATURES:
One valve design functions as a relief valve, by-pass valve, pump backpressure valve, anti-siphon valve, and backpressure regulator.- Relief: protects systems and equipment from over-pressure/pressure surges.
- By-Pass: prevents pumps from "dead heading".
- Back-Pressure: maintains necessary reverse pressure in closed loop systems.
- Anti-Siphon: Used on the outlet of a pump wherever gravity or other downstream conditions may create negative pressure (siphon) and drain a tank. The valve is pre-set to open under pump pressure, but closes bubble-tight when the pump is shut off. Because of the design of the RVDT, this valve actually closes more tightly when unwanted siphon occurs.
- Unique PTFE Diaphragm is excellent for use with highly aggressive liquids...and also provides the ultimate in contamination-free sealing.
- Rugged thermoplastic construction is ideal for a broad range of industrial applications.
- Relief setting is infinitely adjustable from 5 psi to 100 psi.
- Maximum inlet pressure is 150 psi.
- Large diaphragm area delivers more sensitivity and less pressure drop under flow conditions.
- Non-wetted u-cup seal provides a second isolation of the control spring; design includes patented Fail-Dry vent, a safety feature that provides visual warning of seal malfunction. This permits the valve to continue operation until a scheduled maintenance can be planned thereby avoiding a costly shutdown. Fail-Dry connection on Series RVDT is 1/8" FNPT.
- Non-leaching feature of fluoropolymer diaphragm makes it ideal for use with ultra-pure water and concentrated etchants, as in the semiconductor industry.
- Available in 1/4", 1/2", 3/4", 1", 1 1/2" and 2" sizes. For other sizes consult factory.
- Click here for a photographic comparison of the inner workings of Series RVDT vs. competitor's BPV: Not all Backpressure Valves are Created Equal!
Materials of Construction, Manufacturing Process & Quality Assurance:
Series RVDT relief valves are available in Geon® PVC, Corzan® CPVC, Natural Polypropylene (virgin, unpigmented, unfilled PPL), Kynar® PVDF and PTFE body materials. The wetted diaphragm is PTFE energized by a non-wetted FKM diaphragm. Spring housing (not wetted) is PVC. Springs (not in wetted area) are zinc-plated steel, external fasteners are stainless steel. Lock nut and adjusting screw are HDPE on 1/4" - 1" sizes. Lock nut and adjusting screw are stainless steel on 1˝" and 2" sizes. If your environment is incompatible with any of the external materials, or you are interested in some other type of body material, options are available on quantity or special orders.Valve bodies are machined on state-of-the-art CNC lathes and machining centers. Parts are individually inspected prior to assembly. Valves are hand assembled, then inspected. Assembled valves are 100% individually tested (while pressurized) prior to shipment. All operations performed in our plant in Cedar Grove, NJ.
Optional Class 100 cleanroom cleaning and packing including wipe, rinse, Triton flush, nitrogen flush, DI rinse, nitrogen purge/dry, flourescent inspection, capping & 6 mil PE bag and heat seal available upon request. Performed at a certified remote location; priced per valve.
Larger valve shown in photo has a Natural Polypropylene body. Spring housing (completely non-wetted) is Geon PVC, but can be constructed of the wetted body material for a slightly higher cost. Cutaway example in photo is an all-PVC valve.
The standard valves are precision machined from the highest quality brand thermoplastic bar stock with female NPT connections. 1/2" sizes in Geon PVC, Corzan CPVC, Natural Polypro & Kynar PVDF are molded with a choice of FNPT or socket connections. Spigot connections & flare fittings are also available on all sizes. For orders of 25 or more valves, connections can be provided with male threads, sockets, unions, etc. Please consult our Technical Group for more information, (973)256-3000.
Mounting
1/2" size in PVC, CPVC, Natural Polypro & Kynar PVDF have integral mounting lugs on the base of the body, as shown at right. All other sizes & materials have threaded mounting holes in the base.
Gauge Ports & Fail Dry Port
1/2" size in PVC, CPVC, Natural Polypro & Kynar PVDF have opposing 1/8" NPT gauge ports on the side of the body, on the same plane as the piping connections, as shown at right. The gauge ports are not tapped unless so ordered; incurs small charge. On the standard body, the untapped port has no effect on flow or performance. Gauge ports are not readily available on other sizes or on 1/2" PTFE body; please consult factory for alternatives.
The threaded port above the piping connection is the patented Fail-Dry early warning vent. Fail-Dry is standard on all sizes and materials.
Dimensions:
CORZAN: For Corzan CPVC body, change suffix material to -CP.
For example, RVDT050V-PV becomes RVDT050V-CP.
| RVDT MOUNTING HOLE DIMENSIONS |
||||
|---|---|---|---|---|
| Pipe Size |
E IN. MM |
F |  |
|
| Thread Size |
Depth IN. MM |
|||
| ¼" | 1.625 41.3 | 8-32 | .625 15.9 | |
| ½" | 2.97 75.4 | #8 (6mm) | .687 17.5 | |
| ½" (PTFE only) |
1.625 41.3 | 8-32 | .625 15.9 | |
| ¾" | 2.000 50.8 | ¼-20 | .750 19.1 | |
| 1" | 2.000 50.8 | ¼-20 | .750 19.1 | |
| 1-½" | 3.000 76.2 | ¼-20 | .750 19.1 | |
| 1/2" RVDT • PVC, CPVC, PP, PVDF MOUNTING DIAGRAM (BOTTOM VIEW) |
|---|
 |
Flow Reference Charts:
Click image for higher resolution
Click image for higher resolution
For comparison flow curves of Series RVDT vs. competitor's BPV valve, please click here.
HELPFUL LINKS:
Series RVT and RVD -- angle pattern relief valvesSeries RVDM -- rolling diaphragm style relief valves; 1/2" size offers higher pressure ratings
Series RVTX -- a high-capacity 3" size relief valve
What, How, Where & Why of Relief Valves
Explains the application of relief valves as backpressure valves, regular relief, anti-siphon, and how to select a relief valve.
General Relief Valve Page
Provides an overview of the entire line of Plast-O-Matic relief/bypass/backpressure/anti-siphon valves; may be the page you were on prior to this one.
Handy Selection Chart
Graphical chart compares the features, benefits and properties of all Plast-O-Matic relief valves, to assist you in your selection. Page is approx. 120K, so it may take a couple of minutes to load. (It is a copy of the contents page of our Catalog RV, so if you would prefer not to take time downloading, please click on the literature request link below.)
Pressure Regulators
Keep in mind that the RV series is used to control backpressure or "upstream" pressure. If you are looking to control pressure "downstream," aka "outlet" pressure, then please use this link to our Pressure Regulator line. Remember, Relief and Backpressure valves are normally-closed valves for upstream control; Pressure Regulators are normally-open valves for downstream control.
Explanation and diagram of the patented Fail Dry safety vent.
5 Most Common Mistakes When Specifying Valves
This is a very helpful, brief tutorial written by Andy Ryan, Manager of Plast-O-Matic's Technical Group.
Valve Pressure Loss & Flow - Q&A and Equations
(Explains Cv and Delta P, how to better specify valves, etc.)
Plast-O-Matic Valves, Inc.
1384 Pompton Avenue
Cedar Grove, NJ 07009 USA
Voice: (973) 256-3000
Fax: (973) 256-4745
Geon® is a registered trademark of the Geon company,
Kynar ® is a registered trademark of Arkema.,
Corzan tm is a trademark of Noveon.
FAIL-DRY ® and TRUE BLUE® are registered trademarks of Plast-O-Matic Valves, Inc.
Copyright © 1997-2011 Plast-O-Matic Valves, Inc.