Double Check Backflow Preventer Problems

A double check backflow preventer is simply two spring-loaded check valves in a row, with a shut-off valve on either end and test cocks to allow the unit to be tested for proper operation. The double check backflow preventer is the only true backflow preventer which does not have a vent to allow air to enter the lines or to allow water to ...

Double Check Valve Assembly (DCVA ... - IRRIGATION REPAIR

Double Check Valve Assembly: Repair. Each double check valve assembly comes with explicit instructions for maintenance and repair. Rubber components check modules, and seals can be replaced by a mechanically competent homeowner or plumber (if allowed by local code). Many jurisdictions require that any time the access cover is opened for any ...

Double check valve - Wikipedia

Jul 02, 2004· A double check valve or double check assembly (DCA) is a backflow prevention device designed to protect water supplies from contamination.It is different from the two-way check valves (sometimes erroneously referred to as double check valves) used in air brake systems on heavy trucks which select from the highest pressure source.

Problem with double-check valve - DoItYourself.com ...

Sep 22, 2004· The problem I have is the double check valve when the system is under pressure shoots a considerable amount of water out of the test **** in the middle of the cover plate, since this is in a crawlspace I didn't let it run long to see what would happen, but it seemed excessive.

single check or double check valve? | Screwfix Community …

Jun 15, 2017· Hi; a single check valve has 1 non-return ball, double has 2. There will be a slightly greater pressure loss with a double. Assuming you have no h/w pipe blockages or supply problems, to reduce the effect of the valve you could try fitting a 22mm valve with 15/22 reducers before and after it.

Water System Backflow Preventers & Check Valves - DIY …

A second check valve can cause contaminants to be drawn into the piping system, or if the second check valve is inside the well (on the vertical well pipe but above the pump), as in our discussion above it may cause water hammer problems in the system. If the check valve on a submersible pump has failed, you should pull the pump and replace ...

Problem with double-check valve - DoItYourself.com ...

Sep 22, 2004· The problem I have is the double check valve when the system is under pressure shoots a considerable amount of water out of the test **** in the middle of the cover plate, since this is in a crawlspace I didn't let it run long to see what would happen, but it seemed excessive.

Water System Backflow Preventers & Check Valves - DIY …

A second check valve can cause contaminants to be drawn into the piping system, or if the second check valve is inside the well (on the vertical well pipe but above the pump), as in our discussion above it may cause water hammer problems in the system. If the check valve on a submersible pump has failed, you should pull the pump and replace ...

Backflow Troubleshooting - Greater Cincinnati Ohio ...

Backflow prevention assemblies are used to protect water supplies from contamination or pollution. Most common types include the Double Check Valve assembly, Pressure Vacuum Breaker Assemblies, and the Reduced Pressure Assemblies. We service and repair the following backflow device brands: . Ames

Questions and Troubleshooting Answers about Field …

are several problems, which may occur with each of the assemblies being tested: the double check valve assembly, the reduced pres-sure principle assembly and the pressure vacuum breaker assembly. The testing procedures for each of the assemblies, including trouble-shooting will be examined briefly in this article. The Double Check Valve Assembly

BASIC PNEUMATIC MAINTENANCE AND TROUBLESHOOTING …

Check Valves and Flow Controls. Standard check valves; air compressor isolation check valve, rotary screw inlet check valve; check valves used as relief valves; pilot operated check valves; check valve failures; fixed orifice flow controls; needle valves, variable orifice flow controls; meter out flow control circuits; flow control troubleshooting.

Chapter 17 - Control Valve Troubleshooting | Engineering360

Control Valve Troubleshooting. When approaching the troubleshooting of problems associated with automatic control valves, you should use a systematic approach so obvious factors are not overlooked. This chapter addresses the subject of troubleshooting in four ways: Prevention, rather than cure; Types of problems; Methods for diagnosing problems ...

Heart valve surgery - Mayo Clinic - Mayo Clinic - Mayo Clinic

Valves that don't open or close properly disrupt blood flow through your heart to your body. In heart valve surgery, your surgeon repairs or replaces the affected heart valves. Many surgical approaches can be used to repair or replace heart valves, including open-heart surgery or minimally invasive heart surgery.

BALL VALVE TROUBLESHOOTING GUIDE

134 BALL VALVE TROUBLESHOOTING GUIDE Spears® True Union, Single Entry and Compact Ball Valves are designed and produced for trouble-free operation and use. However, certain aspects of installation and application can result in valve malfunctions. This guide identifies some of the more common problems encountered and their necessary corrective actions.

RP/IS-007 Installation, Maintenance, & Repair Series 007 ...

Installation, Maintenance, & Repair Series 007 and LF007 Double Check Valve Assemblies Sizes: 1⁄2" – 3" (15 - 80mm) NOTICE For Australia and New Zealand, line strainers should be installed between the upstream shutoff valve and the inlet of the backflow preventer. 3⁄4" 007M3QT RP/IS-007

Check Valves - Valves - The Home Depot

The SharkBite Check Valve is a general purpose, The SharkBite Check Valve is a general purpose, spring loaded check valve that can be installed in seconds on copper CTS CPVC and PEX. The SharkBite check valve can be installed horizontally or vertically and prevents the reverse flow of water through the water supply line.

AIR BRAKE SYSTEM TROUBLESHOOTING

a. Repair air leak. b. Check governor for proper “cut-in,” “cut-out” pressure and excessive leakage. Repair or replace governor. c. Check to see if air is passing through check valve. d. Check to see if air passes through discharge line. Check for kinks, bends, excessive carbon deposits. Clean or replace discharge line. 2) Water and ...

Installation, Operation, IOM-A-BPA Maintenance and …

DOUBLE CHECK VALVE ASSEMBLY, DOUBLE CHECK DETECTOR ASSEMBLY, REDUCED PRESSURE ZONE ASSEMBLY, AND REDUCED PRESSURE DETECTOR ASSEM-CAUTION: The installation and maintenance of any Ames back-fl ow prevention assembly should be performed by a qualifi ed licensed technician. Failure to do so may result in a malfunctioning assembly.

BENDIX DOUBLE CHECK VALVES MANUAL Pdf Download | ManualsLib

Page 1 DESCRIPTION As air under pressure enters either end of the double check Double check valves are used in an air brake system to valve (inlet port) the moving shuttle or disc responds to the direct a flow of air into a common line from either of two pressure and seals the opposite port, assuming it is at a sources, whichever is at the higher pressure.

Testing Procedures & Trouble Shooting Guide

Double Check Backflow Preventer (½” – 2”) First Check Valve Test . 1) Bleed all test cocks. 2) Attach high side hose with bleed off valve to TC2. Then, bleed TC2 through the high side needle valve. 3) Open TC3 and let the water run out, then close TC3. 4) Close SOV2. Hold the test gauge such that the center of the test gauge is at the same

950XL - 2" - 2" | Backflow Parts USA

Repair Parts are available below. Wilkins: 2" 950XL Double Check Valve Assembly Sku# 2-950XL NOTE: This assembly is not lead free compliant and should only be …

BASIC PNEUMATIC MAINTENANCE AND TROUBLESHOOTING …

Check Valves and Flow Controls. Standard check valves; air compressor isolation check valve, rotary screw inlet check valve; check valves used as relief valves; pilot operated check valves; check valve failures; fixed orifice flow controls; needle valves, variable orifice flow controls; meter out flow control circuits; flow control troubleshooting.

950XL - Zurn

950XL. The Zurn Wilkins 950XL Double Check Valve Assembly is a wye pattern backflow preventer used in low hazard, non potable applications.

Understanding Check Valves: Sizing for the Application ...

Valves; Understanding Check Valves: Sizing for the Application, Not the Line Size. Check valves are probably the most misunderstood valves ever invented. If you mention check valves to most plant personnel, the typical response is “they don’t work.

Check Valves: Repair or Replace?

To remove and replace check valve seats reliably and in a cost-effective manner, the valve repair vendor must utilize custom tooling, procedures and techniques. Utilizing this special tooling, craft personnel have performed numerous successful seat replacements on check valves, ranging in size from 12-inch NPS to 50-inch NPS.

Flood Control | Chicago & Suburbs | The Scottish Plumber

Another flood control system Chicago area customers often choose is the Double Check Valve system. These systems are installed outside of the home, usually in the front yard. A concrete basin is installed over your sewer. Inside this basin, a pump and two check valves work to ensure that the flow of your sewer line is directed away from your home.

Tractor Troubleshooting Guide

Check anti-compound double check valve # 18. Check #17 for back flow into service control line. Check trailer air system for back flow into tractor’s service control line. CAUTION: CHOCK WHEELS - Repair and replace items as necessary. LEAKS AT EXHAUST WITH HAND VALVE APPLIED Check double check valve #20 or #21. Repair or replace.

289714X - Quick Release Valve - Haldex product

Double Check Valve prevents simultaneous application of the emergency side of the spring brakes (Anti-Compounding). Supply and delivery differential is 1 PSI max. KN32041 Valve may also be used for this application. Crack Pressure 1 PSI. Approximate Weight 1.2 lbs. Notes. Available CoreFree™, order part number 289714RX. Repair Kit not available.

Installation, Operation, IOM-A-BPA Maintenance and …

DOUBLE CHECK VALVE ASSEMBLY, DOUBLE CHECK DETECTOR ASSEMBLY, REDUCED PRESSURE ZONE ASSEMBLY, AND REDUCED PRESSURE DETECTOR ASSEM-CAUTION: The installation and maintenance of any Ames back-fl ow prevention assembly should be performed by a qualifi ed licensed technician. Failure to do so may result in a malfunctioning assembly.

Backflow Prevention - Apollo Valves

The "Apollo ®" Advantage "Apollo ®" Valves' backflow prevention devices are best in class, in terms of ease of maintenance.They utilize minimal size and shape. Additionally, "Apollo ® "'s backflow preventers process superior pressure drop ratings, boast an industry leading five-year warranty, and are domestic bronze and stainless steel constructed and assembled in the U.S.A.

Check Valves - Valves - The Home Depot

The SharkBite Check Valve is a general purpose, The SharkBite Check Valve is a general purpose, spring loaded check valve that can be installed in seconds on copper CTS CPVC and PEX. The SharkBite check valve can be installed horizontally or vertically and prevents the reverse flow of water through the water supply line.

Testing Procedures & Trouble Shooting Guide

Double Check Backflow Preventer (½” – 2”) First Check Valve Test . 1) Bleed all test cocks. 2) Attach high side hose with bleed off valve to TC2. Then, bleed TC2 through the high side needle valve. 3) Open TC3 and let the water run out, then close TC3. 4) Close SOV2. Hold the test gauge such that the center of the test gauge is at the same

Double Check Valve Assembly (DCVA) | Sprinkler School

This article discusses underground and above ground installations of a double check valve assembly. DCVA- Underground Installation: Before installation, run the main irrigation supply line from the isolation valve to the vicinity of the DCVA valve box. Temporarily seal the end of the pipe to keep out soil and debris. Install a rectangular irrigation box […]

007 - Watts

Series 007 Double Check Valve Assemblies prevent the backflow of contaminated water into the potable water supply. They have a bronze (1/2 to 2 in.) body construction that is easy to maintain and service. Series 007 is ideal at referenced cross-connections identified as non-health hazard applications.