• Product-Specific FAQ's

    Here you'll find answers to some of the most frequently asked questions; check back often as we'll make updates as new questions arise.

    Yes and No. Yes, if the modification directly affects the functionality of the valve. No, if for example, you are adding an external item such as a Babbitt sprocket to a UL listed valve for remote operation. UL valves can be repaired, provided the repair parts are obtained directly from the manufacturer.

    NIBCO only quotes Barrier PEX in our radiant systems due to the risk of cast iron being anywhere in the system. Users run the risk of sludge building up in the pipe system and the cast iron will be ruined by oxygen building up and rusting the iron. NIBCO® Barrier PEX acts as a barrier against the buildup of the oxygen molecules stopping them from accumulating in the radiant system. 


    A gate valve is used to stop the flow of a moving fluid. They cannot be used to partially interrupt the flow (called throttling) and must be used in either the completely open or completely closed position.

    A globe valve is used to throttle somewhere between the open and closed position. Globe valves offer a compression seal; when the stem is turned, the seat gets compressed, providing a better seal.

    A check valve is used to prevent backflow. These valves do not have operating mechanisms because the valve operates automatically, depending on the pressure of the flow.

    A ball valve can be used the same way gates and globes can be used, however they are typically less expensive. A ball valve has several advantages over gates and globes. They are ¼-turn instead of multi-turn. The position of the lever handle indicates whether the valve is open or closed.

    A butterfly valve is used in similar applications as the gates and globes, but has several advantages over the gates and globes. Like ball valves, they are ¼-turn instead of multi-turn. Butterfly valves are lighter in weight and take up very little space in the line. They also have throttling capabilities and resilient sealing.


    A resilient wedge is necessary when a bubble-tight seal is needed. Metal-to-metal seated valves have an allowable leakage rate which means they are not required to seal off the flow of material completely.

    ABS and PVC are both used in DWV (Drain, Waste, Vent) service. ABS is colored black and PVC is colored white. Some local codes require PVC over ABS because the color white makes it easier to look at a joint and see that the purple primer has been applied. Both ABS and PVC DWV carry the Schedule 40 wall thickness, but they are not rated for pressure. ABS and PVC can be threaded together, but not glued together. ABS, PVC, and CPVC CTS take different solvent cements.

    Schedule 40 and Schedule 80 fittings refer to the wall thickness of the fitting. The higher the schedule, the thicker the wall will be. The schedule of the wall affects the ID of the pipe, not the OD. Schedule 40 and 80 threaded fittings can be joined together provided the OD of the fittings are the same.

    CTS stands for Copper Tube Size. CPVC-CTS fittings are designed to be used in residential applications to replace copper pressure fittings. CTS fittings cannot be joined with ABS, PVC, Schedule 40 or 80 fittings. The dimensions of the cups are different.

    PEX tubing that is manufactured by NIBCO is labeled with the manufacture date directly on the tubing. NIBCO started producing PEX on May 15, 2006. PEX tubing made prior to that date was made by CPI (Consolidated Plumbing Industries – a disbanded company). Only NIBCO® PEX made after May 15, 2006, could have been manufactured by NIBCO.

    The ¼-turn valves have the advantage of quick shut-off of the flow, but there is a risk of water hammer or shock if the valves are closed too quickly. When the flow is abruptly stopped, the energy in the medium hits the valve and reverberates through the line. This can damage the piping system. The multi-turn valves close slowly, eliminating the water hammer.

    High performance butterfly valves have carbon steel bodies, adjustable packing, offset disc design, PTFE seats, and are sometimes suitable for steam service. Standard resilient (rubber) seated butterfly valves do not have those features, but are less costly and perform just as well for in-applications for which they are intended and compatible.

    High performance butterfly valves have carbon steel bodies, adjustable packing, offset disc design, PTFE seats, and are sometimes suitable for steam service. Standard resilient (rubber) seated butterfly valves do not have those features, but are less costly and perform just as well for in-applications for which they are intended and compatible.

    Not all copper fittings can be formed using the wrot process. For example, a drop ear elbow is difficult to form using the wrot process, so it is poured and cast in a mold. Other fittings such as a 90 degree elbow can be formed using the wrot process. It would not be cost-effective to offer those fittings as cast copper.

    A one-piece ball valve has no potential body leak paths, but requires the use of a reduced port ball. This valve is not repairable. Once the valve fails, it must be replaced.

    A two-piece ball valve is the most popular due to the lower cost of manufacturing. It is available in both full port and conventional port. This valve is not repairable. Once the valve fails, it must be replaced.

    A three-piece ball valve is more costly, but is easier to disassemble and offers in-line repair ability. This valve is available in full port and conventional port.