Automatic degassing Air Valve Type 100
Air valves available in 4 models: model 100, model 110, model 111, model 112 and model 113
The Automatic Degassing Air Valve is used on pressurized pipes to evacuate the air or a mix of air/water accumulated in the high points of the pipeline during normal duty. It has to be fitted on each track peak, meant as slope changing.
Technical design
| 100 | 16 | ¾ | 138 | 161 | 4.5 | 204001 |
| 100 | 25 | ¾ | 138 | 161 | 4.5 | 204003 |
| 100 | 16 | 1 | 138 | 161 | 5 | 204005 |
| 100 | 25 | 1 | 138 | 161 | 4.5 | 204007 |
| 110 | 16 | ¾ | 138 | 184 | 4.5 | RCF07AEAH |
| 110 | 16 | 1 | 138 | 184 | 4.5 | RCF10AEAH |
| 110 | 25 | 1 | 138 | 184 | 4.5 | RCF10AEDH |
| 111 | 16 | ¾ | 138 | 230.5 | 4.5 | RCF07BAAH |
| 111 | 25 | ¾ | 138 | 230.5 | 4.5 | RCF07BNDH |
| 111 | 16 | 1 | 138 | 230.5 | 4.5 | RCF10BNAH |
| 111 | 25 | 1 | 138 | 230.5 | 4.5 | RCF10BNDH |
| 112 | 16 | 1 | 215 | 138 | 7.5 | RCA40AFAH |
| 112 | 25 | 1 | 215 | 138 | 10.1 | RCA40AFDH |
| 112 | 16 | 1 | 218 | 138 | 10 | 204010 |
| 113 | 16 | 1 | 262.5 | 138 | 8 | RCA40BTXH |
| 113 | 25 | 1 | 262.5 | 138 | 10.1 | RCA40BTCH |
| 113 | 16 | 1 | 265.5 | 138 | 10.5 | 181190 |
| 113 | 25 | 1 | 265.5 | 138 | 11 | 204009 |
| 113 | 25 | 1 | 265.5 | 138 | 12 | 181597 |
Features
Material and coating
| Item | Designation | Material | Coatings |
|---|---|---|---|
| 1 | Body | Ductile iron FGS 400/15 or 500-7 | Blue Epoxy 250 microns |
| 2 | Cover | Ductile iron FGS 400/15 or 500-7 | Blue Epoxy 250 microns |
| 3 | Screw | Stainless steel A2 | |
| 4 | Washer | Stainless steel A2 | |
| 5 | Float | ABS | |
| 6 | Nozzle | Polyamide | |
| 7 | Nut | Polyamide | |
| 8 | Gasket | EPDM | |
| 9 | O ring | EPDM | |
| 10 | Gasket | EPDM | |
| 11 | Adjusting screw | Stainless steel A2 | |
| 12 | Pin | Stainless steel A2 | |
| 13 | Air valve | Brass |
Performances
Applicable Standards
Hydraulic test
Every single air valve is subjected to hydraulic test in accordance with the prescription EN 1074:
- Test of float at minimum declared pressure according to EN 1074-1 standard (0,5 bar).
Product test
- Control of coatings: test of thickness, holiday test, impact test, MIBK test.
Conformity to the standards
Product:
- EN 1074-1
- EN 1074-4
Flanges connection:
- EN 1092-2
- ISO 7005-2
Suitability for potable water:
- D.M. 174 for applicable parts (ex : C.M. 102 du 02/12/78)
- Conformity with foreign norms: KTW (Germany), WRC (UK), ACS (France)
Marking
On the body:
- Type of ductile iron
- Model code
- Manufacturer's logo
- Fusion date
On the labels:
- Nominal diameter in mm (DN)
- Nominal pressure in mm (PN)
- Maximum operating pressure (PFA)
- Production number
- Manufacturer's logo
Valves selection
The operating pressure value (PFA) is defined depending on the pressure of the pipeline. Moreover this is important to verify that the operating temperature is between 0° C and 40°C.
The maximum flow allowable depends on air valve PFA and is calculated using the formula:
Q = v*A; where “v” is the outlet air speed from a small orifice (measured: 195 m/s) with pressure more than 1,3 bar.
| PFA | Orifice Diameter (mm) | Max Flow (m3/h) |
|---|---|---|
| 25 | 1,75 | 1,69 |
| 16 | 2,25 | 2,79 |
To evaluate if a single vent is enough, it must be check the air flow which is to be evacuated, which depends on the devices fitted on the pipe (i.e. pump thrust, etc…) and the solubility of air in water (Bunsen coefficient, function of temperature and pressure).
Instructions for use
Storage
The air valve will have to be stored (if possible) in covered places, as possible protected from the sun and from the rain and generally from the atmospheric agents. Moreover it will have to be avoided that the seal of the air valves are in contact with dust or gravel.
Installation
The automatic degassing air valve is installed where the pipe have a slope variation, for eliminating the air balls which can be accumulated in the higher points or moving inside the duct.
Maintenance
In order to grant the possibility of future inspections, it is necessary during the installation to fit a manual sectioning device (i.e. gate valve or butterfly valve) between the pipe flange and the air valve. In this way it will be possible to maintain without interrupting service. It is important to make sure that air valve can be dissembled while the pipe is still in service.
