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Protects from water hammer effects in the pipeline system, in situations such as
column separation, deep well pumping and rapid filling of mains.
The NS mechanism is suitable for A.R.I combination air valve models:
D-010HF, D-012HF, D-060HF, D-060-CHF, D-062HF and kinetic air valve models:
K-010HF, K-060HF, K-062HF.
In 2" ,3", 4", 6", 8" diameter.
It is suitable for PN-16 and PN-25.

Operation in Deep Well Pumping:

In a deep well, the long suction pipe in the well shaft is full of air. As water is pumped
rapidly up the suction pipe, air is forced through the pump air valve in great velocity.
If the air valve were to slam shut suddenly, by the approaching water, instantly
reducing velocity to 0, it could cause a severe water hammer or surge. The kinetic
element of the "Non Slam" air valve shuts in two stages, slowing down the air
discharge during the second stage, thus, dissipating the air pocket slowly. The
slowly dissipated air pocket cushions the closing of the second stage, as water
approaches the float, thus preventing the local water hammer or surge.

Operation under column separation situation :

Column separation can occur due to changes in flow condition or/and drainage of
the pipe line. The water column will split at an apex point creating a vacuum cavity.
After some time the sub-atmospheric pressure pulls the separated water columns
back, and they collide. The collision creates a water hammer wave that can burst
the pipe.
If the "Non Slam" Air Valve is mounted on the pipe at his apex point it will prevent
this water hammer from occuring:
1. when column separation occurs the large orifice introduces large quantities of
air into the vacuum bubble and reduces the sub-atmospheric pressure.
2. When the water columns change direction and start moving back towards
collision, air is exhausted rapidly through the air Valve, creating a differential
pressure higher than 1.0 meter across the Air Valve orifice.


3. The "Non Slam", first stage, partially closes the air outlet, allowing only a slow
discharge of the air entrapped in the pipe. This air pocket dampens the velocity
of the approaching water columns, and acts as a shock absorber that prevents
water hammer.


Flow Control Accessories

Kfar Charuv, 12932 Israel Tel. 972-6-6761988 Fax. 972-6-6763402

Operation in rapid filling of the pipeline:

1. When water, rapidly filling the pipe line,

pushes the air out through the Air Valve, a
differential air pressure is created across the
valve orifice.

2. When this differential pressure reaches a

prefixed level (usually it will be prefixed at 0.05
bar) the orifice disc will close.

4. When water reaches the kinetic float, it lifts

it up, closing the kinetic orifice and completing
the kinetic cycle.

6. When water is drained out of the pipe line,

the resulting pressure drop lets the kinetic
float fall down, opening the orifice fully for
intake of high volume of air into the line.

5. The "vented Check Valve Orifice Disc" will

come back to its normal open position.

3. Air will continue to come out through a the small

orifice disc - until all the air will be exhausted
and water will reach the kinetic float. This double
stage kinetic air discharge prevents the slam
effect and therefore suppresses water hammer.