Frequently Asked Questions
Q. "How durable and reliable are these check valves?"
A. There are many qualities of plastics, and you can be assured that we only ship top-of-the line plastics. Having said that, these are made out of plastic and this material has pro's and con's. These will degrade in sunlight over time, unlike brass valves. These, under normal wear and tear, in most situations, "should" last at least 2-7 years. Quality brass valves will last longer under most conditions (not in aggressive water conditions). For sewage, ponds, fountains and sump pump applications, we believe that our above PVC swing checks are the best product for the conditions that these are exposed to.
Q. "Do you recommend using PTFE thread sealing tape on PVC threads?"
A. Lasco Manufacturing says: "It is wrong to add excess bulk to a threaded joint by wrapping male threads in Teflon® tape. It is wrong to make over-tightening easier by using Teflon® tape..." We have seen much similar PTFE thread sealing tape used satisfactorily but cannot (due to liability potential) recommend that you use PTFE thread sealing tape (pipe dope designed for PVC, such as we offer above, is acceptable).
Q. "Can I glue PVC if it is wet?"
A. All solvent cements have the ability to absorb some water and still perform well enough to accomplish an adequate joint. However, research shows that the presence of just 10% water in solvent cement can slow penetration and swelling by up to 65%. This joint, with water inside, will always be an inferior joint and subject to problems.
Q. "Can I use PVC glue on other plastics?"
A. We only recommend using glues manufactured for a specific plastic i.e. PVC glue only on PVC pipe.
Note: There are many plastics that cannot be glued at all; polyethylene, polypropylene, nylon, polybutylene, and other polyolefins.
Q. "What is LO-V.O.C.?"
A. LO-V.O.C. cements produce significantly less amounts of "V.O.C.'s". V.O.C. stands for "volatile organic compounds", which are unhealthy when breathed or induced. V.O.C.'s also diminish air quality. Please read and follow all directions carefully when applying these cements.
Q. "Do I really need to use primer?"
A. Primer is a mixture of solvents used to penetrate the pipe and fittings and start the swelling process ahead of the application of the solvent cement. It is highly recommended that you use primer.
Q. "Do you offer PVC primer?"
A. We have not found a brand of primer that we are confident will not leak in transit. It is highly flammable and, in our opinion, too dangerous to ship.
Q. "How do I glue PVC fittings and valves to the pipe?"
A. Most PVC manufacturers recommend that the installer follow the instructions for the cement and primer that is being used. Their instructions are usually found on the label of the container.
Q. "What does Comp x Comp, Fips x Fips and Solv x Solv mean?"
A. Solv x Solv = solvent (glue to hold in place) type; Comp x Comp = compression style is easy to install; Fips x Fips = is threaded (female) style.
Q. "What is the difference between Spring vs. Swing?"
A. Spring loaded means it has a spring. It tends to seal better (best for potable water pumps), but the spring will wear out easier and does take more pressure to open it. A swing check works on the gravity principle (more reliable in the long run), and it take less pressure to open it, minimizing pressure loss (best for sump, pond, fountain, sewage pumps). A swing check can be used for horizontal or vertical mounting for fluid flowing upward. However, swing check valves are not recommended for applications where frequent reversal of water flow occurs as this can cause the valve (swing disk) to fluctuate rapidly resulting in valve chatter or water hammer noise. Spring check valves are better suited for this type of application and may also be installed horizontally or vertically with upward fluid flow.
Q. "What is a Hastelloy® spring?"
A. It is a spring made with the super metal alloy Hastelloy®, a registered trademark of the Haynes International Inc. company who created this and many other high performance, corrosion resistant alloys. The spring is made from stainless steel, along with other alloys, and is designed to endure high temperatures, high stress, and severe corrosion applications.
Q. "The deluxe version of the corrosion resistant check valve has a CPVC body. Can I connect this to regular PVC Sch.40 piping?"
A. Yes, the deluxe version of the corrosion resistant check valve can be used on iron pipe sized (IPS) Sch. 40 PVC pipe or CPVC piping. However, if the check valve is used with CPVC piping then CPVC cement and primer must be used to meet the temperature requirements of the piping. If connecting to PVC piping then PVC cement and primer can be used. The manufacturer says the deluxe #0801-20H2 CPVC check valves have been used in thousands of pool and spa applications and PVC glue is being used to plumb the vast majority of them.