Spin-Out Filters
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      Transitioning SPIN-OUT Filters to Threaded Connections

      Transitioning SPIN-OUT Filters to Threaded Connections

      SPIN-OUT filter units are typically supplied with SLIP inlet and outlet connections.

      AVOID FPT BUSHINGS:

      When NPT threaded connections are desired, it is wise to avoid solvent welding in a PVC Spigot x FPT bushing to convert the filters slip (socket) connections to NPT thread.

      When you need to transition the solvent weld inlet or outlet connection to a threaded connection it is best practice to avoid having a plastic female (FPT) fitting. When a threaded pipe or male fitting gets overtightened it will result in a stress crack either immediately or over time due to the extreme internal pressure created by the tapered NPT threads. Most often the stress crack will also destroy the filter head. Either way, when a female threaded fitting is solvent welded in, any stress crack will require a costly replacement of the entire filter unit.

      SOLUTIONS:

      A much more durable and trouble free connection can be made by transitioning to an MPT plastic thread or to use a PVC to metal transition adapter fitting. Below are a few viable solutions.

      #1 – The easiest and most cost effective is to use two Series 433-xxx PVC MPT x SPIGOT Adapters

      #2 – The same can be achieved by cutting a Schedule 80 Pipe nipple in half and gluing the plain end into the socket. The downside is that the nipple color will be gray. The plus side is that by using a long enough nipple you can have enough PVC pipe to repair a connection in the future if the thread was to be damaged. You can simply cut off the thread and solvent weld on a fitting, avoiding the replacement of the filter unit.

      NOTE: You must use an extruded pipe nipple. Never attempt to glue an injection molded PVC pipe nipple into a socket. The injection molded nipples will have a seem and surface imperfections due to injection gates and ejector pin marks. For more information visit: 

      https://support.boshart.com/are-your-880-series-schedule-80-pvc-pipe-nipples-seamless

      #3 – The third option is to use a PVC to METAL transition fitting. This will be the most expensive option, and Boshart does not carry these fittings. See options below.