
D040.WTR.CAT.ENG06
D-040 PN 16
D-040-C PN 16
Combination Air Valve
Description
e D-040 series Combination Air Valve has the features of both an
air release valve and an air & vacuum valve.
e air release component is designed to automatically release small
pockets of air to the atmosphere as they accumulate along a pipeline
or piping system when it is full and operating under pressure.
e air & vacuum component is designed to automatically
discharge or admit large volumes of air during the lling or draining
of a pipeline or piping system. is valve will open to relieve
negative pressures whenever water column separation occurs.
Applications
- Pump stations: after the pump and after the check valve.
- Downstream (after) and upstream (before) of shut-o valves.
- After deep-well pumps.
- On long constant-sloped pipeline segments.
- At peaks along the pipeline and at peaks relative to hydraulic
gradient.
- At end lines.
- Before water meters.
- On strainers and lters.
D-040-C - additional applications
- Water pipelines vulnerable to vandalism and/or water theft.
- Water systems found in remote areas.
Operation
e air & vacuum component, with the large orice, discharges
air at high ow rates during the lling of the system and admits air
into the system at high ow rates during its drainage and at water
column separation.
High velocity air will not blow the oat shut. Water will lift the
oat, which seals the valve.
At any time during system operation, should internal pressure of the
system fall below atmospheric pressure, air will enter the system.
e smooth discharge of air reduces pressure surges and other
destructive phenomena.
e intake of air in response to negative pressure protects the system
from destructive vacuum conditions and prevents damage caused
by water column separation. Air entry is essential to eciently drain
the system.
e air release component releases entrapped air in pressurized
systems.
Water Supply
Without air valves, pockets of accumulated air may cause the
following hydraulic disturbances:
- Restriction of eective ow due to a reduction of the ow area. In
extreme cases this will cause complete ow stoppage.
- Obstruction of ecient hydraulic transmission due to air ow
disturbances.
- Acceleration of cavitation damages.
- Increase in pressure transients and surges.
- Internal corrosion of pipes, ttings and accessories.
- Dangerous high-energy bursts of compressed air.
- Inaccuracies in ow metering.
As the system lls and is pressurized, the combination air valve
functions in the following stages:
1. Air in the pipeline is discharged by the air valve.
2. Liquid enters the air valve, lifting the oat which pushes the
sealing mechanism to its sealing position.
3. Entrapped air, which accumulates at peaks and along the system,
rises to the top of the air valve, which in turn displaces the liquid in
the air valve body.
4. e oat drops down, unsealing the rolling seal. e air release
orice opens and the accumulated air is released.
5. Liquid enters the air release valve, the oat rises pushing the
rolling seal to its sealing position.
When internal pressure falls below atmospheric pressure
(negative pressure):
1. e oat will drop down, immediately opening the air & vacuum
and air release orices.
2. Air will enter into the system
Main Features
- Working pressure range: 0.2 - 16 bar
- Testing pressure: 25 bar.
- Maximum working temperature: 60° C.
- Maximum intermittent temperature: 90° C.
- Reliable operation reduces water hammer incidents.
- Dynamic design allows for high capacity air discharge while
preventing premature closure.
- Lightweight, small dimensions, simple and reliable structure.
- e discharge outlet enables the connection of a vent/drain pipe.
- e large size of the automatic air release orice relative to the air
valve body:
• Discharges air at high ow rates.
• Lessens the danger of its obstruction by debris.

D-040
• Enables the usage of the rolling seal mechanism, making it less
sensitive to pressure dierential than a direct oat seal.
- e body is made of high-strength composite materials and all
operating parts are made of specially selected, corrosion- resistant
materials.
- Due to its light weight, the valve may be installed on plastic piping
systems, as well as other lightweight piping systems.
- D-040-C the body is protected in a metal shell for anti-vandalism/
theft applications.
Valve Selection
e air valve is available with:
- Wide size range: 1/2”, 3/4”, 1”, 2” threaded male connections,
NPT or BSPT.
- Optional ball valve tap; BSPT or NPT male connection.
Options
- e D-040 air valve is available in the following options:
• D-040 1”& 2” - reinforced nylon body and base
• D-040 B 1”& 2” -reinforced nylon body and brass base
• D-040 C 1”& 2” - ductile iron shell and base (1”base - brass)
• D-040 ST. - reinforced nylon body and stainless steel base
• D-040 ST ST - stainless steel body and stainless steel base
- D-040 LP air valve is designed for very low pressure systems with a
maximum working pressure of PN 6
- DG-10 air valve is designed for low pressure systems with a
maximum working pressure of PN10
- D-040 HT air valve (rated PN10) is designed for hot water
systems with a maximum working temperature of 90°C.
Note
For best suitability, it is recommended to send the uid chemical
properties along with the valve request.
Upon ordering, please specify: model, size, working pressure, thread
and ange standard and type of liquid.

D-040
ACCESSORIES
Ball Valve
Shut-o valve: Made of brass ATSM B-124
Suitable for: D-040 1” 2”
D-040-C 1” 2”
Flanges
Made of Reinforced Nylon / Cast Ductile / ST. 37
Suitable for: D-040 1” 2”
D-040-C 1” 2”
Diameter 40/50/60 Internal threads: 3/4”, 1”, 2”
Diameter 40/50/65 Internal threads: 3/4” 1” 2”
Diameter 50mm Internal threads: 1” 2”
Diameter 80mm Internal threads: 2” 3”
Thermal Protection Jacket
Made of polyurethane
Extension
Available with extended pipe.
One-way models
e D-040 series air valve is available as:
D-040 P T 2”
D-040 P T 1”
D-040-C T 2”
D-040-C T 1”
e D-040 series air valve is available as:
D040-V With a one-way, out-only attachment, allows air discharge
only, prevents air intake (all models).
D-040-I With a vacuum breaker, in-only attachment, allows air
intake only, not allowing air discharge (D-040 2” only).
D-040-NS With a non-slam, discharge-throttling attachment, allows full air intake, throttles air discharge (D-040 2” only).
D-040 Non-Slam Single Orice Add-on Component Data Table
Model Nominal
Size
D-040 NS 2” (50mm) 37.5 mm 12.6 mm
Discharge
orice
Total NS
area
NS orice Switching
2
4 mm Spring loaded
point
normally closed
D-040-NS 2”
Flow at
0.4 bar
17.5 m3/h

D-040
D-040 1" D-040 2" D-040 ST ST 1" D-040 ST ST 2"D-040 B 2" D-040 ST 2"
DIMENSIONS AND WEIGHTS
Model Dimensions mm Connection Weight Orice Area mm
2
A B C Kg. Auto. A / V
1/2” 3/4” 1”
D-040 100 143 3/8”
D-040 B 100 143 3/8”
D-040 ST 100 143 3/8”
D-040 ST ST 94 139 3/8”
BSP Female 0.33 7.8 100
BSP Female 0.70 7.8 100
BSP Female 0.65 7.8 100
BSP Female 1.00 7.8 100
2”
D-040 P 183 215 1½”
D-040 B 183 215 1½”
D-040 ST 183 215 1½”
D-040 ST ST 183 215 1½”
BSP Female 1.10 12 804
BSP Female 1.80 12 804
BSP Female 2.10 12 804
BSP Female 3.10 12 804
* All product weights are approximate due to the dierences in ange standards and
variable accessories
PARTS LIST AND SPECIFICATION
No. Part Material
D-040 / B / ST
Material
D-040 ST ST
1. Body Reinforced Nylon Stainless Steel 316
2. Discharge Outlet Polypropylene Polypropylene
3. 1/2” 3/4” 1” Rolling Seal EPDM Viton / BUNA-N / EPDM
2” Rolling Seal assembly:
3a. Screws Stainless Steel Stainless Steel
3b. Plug Cover Reinforced Nylon Polypropylene /Reinforced Nylon
3c. Rolling Seal EPDM Viton / BUNA-N / EPDM
3d. Plug Reinforced Nylon Polypropylene / Reinforced Nylon
4. Clamping Stem Reinforced Nylon Polypropylene / Reinforced Nylon
5. Float Foamed Polypropylene Foamed Polypropylene
6. O-Ring BUNA-N BUNA-N
7. Base Reinforced Nylon
Stainless Steel 316
/ Brass
/ Stainless Steel 316
A
1
2
3
C
4
5
B
6
7
A
3 21
C
4
B
5
6
7
3c
3b
3a
Optional Ball Valve Brass Nickel plated
3d