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Discontinuation of Duo-Bloc ball valve

In order to meet the latest industry requirements, and customer demands we have decided to discontinue the Duo-Bloc ball valve.

Both PVC and CPVC models of the Duo-Bloc Ball Valves (1/2" – 2") will be discontinued in the near future. The Duo Bloc will be replaced by the Type 21 Ball Valve, which has many added Features and Benefits as outlined below.


We will maintain inventory of the Duo-Bloc until the end of the 1st Quarter March 2003.

Parts Availability:

We will be able to supply replacement parts for a period of five years effective the 2nd quarter of 2003.


The Type 21 valve will be priced the same as the Duo-Bloc, even withthe additional features and benefits.


TheType-21 (1/2" – 2") will not have parts or face to face dimension interchangeability. (Socket and Threaded Versions only) Flanged models will have face to face dimension interchangeability only, but no parts interchangeability.

Features and Benefits:

  • Increased Pressure Rating – Type-21 (1/2" – 2") PVC and CPVC are rated for 230 psi maximum working pressure.
  • Built-in Spanner Wrench – Valve handle doubles as carrier adjustment or removal tool when maintenance is required.
  • Double O-ring Stem seals – The Type-21 has Double O-ring stem seals that increase operator safety in severe applications.
  • Single Carrier Design – Only one carrier to adjust which insures the ball is centered within the body.
  • Improves field safety when used as a blocking valve as it eliminates a threaded connection or potential leak path.
  • ISO Mounting Pad – The Type-21 valve has an integral molded ISO mounting pad. Simply removal the handle and it allows easy mounting of accessories or automation, with no valve modifications required.
  • Panel Mount Provision – There is a molded platform on the bottom of the Type-21 that accepts self-tapping threaded inserts. This allows for supporting the valve to a panel or wall.

Type 21-Valve Accessories

  • Actuation ( Electric and Pneumatic)
  • 2" square operating nuts and T-nuts
  • Locking devices
  • Manual limit switch kits
  • Panel mount stem extensions
  • Single and 2-piece stem extensions, in a variety of materials.
  • Optional O-ring materials
  • Vented Ball (Sodium Hypochlorite Service)

If you have any questions or concerns, please consult your Asahi/America District Manager, or our Customer Service Department.