Anti hammer three function air valve for sewage in stainless steel AISI 316 Mod. SCS-AS 2" - PN 16

The air valve guarantees the proper operation of sewage lines allowing the entrance of large air quantity in case of pipe bursting or draining phases, the release of air pockets during working conditions and the controlled air outflow speed.

Construction and  advantages

  • Lower body designed  with strongly  sloped walls to avoid  grease  and/or   other   material   deposit.
  • Upper  body  containing the  air release device  in stainless steel  A S  316 which is protected against projections, during  rapid  filling phases by an  s.s. diffuser.
  • Mobile block including a shaft  and  a large  float, both in stainless steel A S  316, placed  on the lower body and  connected to the air release mechanism and to the main orifice obturator.
  • Anti Shock  automatism composed of a metallic disk with 2 or more small orifices, a guide bar and a counteracting spring in stainless steel.
  • Drainage valve  for chamber control  and  draining.
  • Maintenance can  easily  be  performed from the  top without  removing   the  air  valve  from  the  pipe.
  • Evacuation bend  suitable for flooded environments with 1" threaded outlet.


Operating principle

  1. Entrance of large volumes of air
    During pipeline  draining  or bursting  phases it is necessary to bring  in as much  air as the quantity  of out-flowing  water  to  avoid  vacuum conditions.
  2. Controlled air discharge
    The SCS-AS air valve is provided  with a mechanism called AS. During vacuum conditions the mobile block is laid over the  diffuser,  the  anti-shock disk comes down pulling the stainless steel  spring  and  allows the  entrance of a large  volume  of air through  the main  orifice  to  compensate the  vacuum effect.
  3. Air release during working conditions. During operation, an air pocket   accumulates in the upper  part of the valve body, little by little it is compressed and its pressure arrives  at water pressure, its volume increases pushing the water  downwards. Following Archimede's principle the float, no longer sustained by water thrust,  will drop freeing the nozzle  hole helping the release of the air pocket,  while the upper  disk closes the   main   orifice   due   to   internal   pressure.

For air flow performances of SCS-AS 2" please refer to the chart depicted on the next page.

Working conditions
Waste water 70 oc/ 1
58 oF Max; Maximum pressure 16 bar/ 232 psi; Minimum pressure 0,35 bar/ 5.2 psi.

Technical features
Lower body and upper body entirely made in stainless steel AISI 316 passivated
Obturator in polypropylene
Nozzle and gasket holder in stainless steel  AISI 316
AS  guide  bar  and  spring   in  stainless  steel
AS disk  in brass/stainless steel
Float and  rod  in stainless steel AISI 316
Gaskets in NBR
Sealing seat in stainless steel AISI 304 / AISI 316
Drainage valve in galvanized brass or stainless steel AISI 316