CSA B125.3-2012 pdf free download

CSA B125.3-2012 pdf free download.Plumbing fittings.
5.9.2.3 Test procedure for anti-siphon fill valves with air gaps or vacuum breakers
If the specimen incorporates an air gap or a vacuum breakei, the following loads shall be applied in sequence with the valve held fully open:
(a) Apply and hold a vacuum (expressed iii pressure below ambient) of 85 kPa (12 psi) for 5 mm and then allow the pressure on the supply side of the specimen to return to atmospheric.
(b) Raise the vacuum test load gradually from 0 to 85 kPa (0 to 12 psi) and then gradually reduce it to o kPa (0 psi) during the test.
(c) Create a surge effect by rapidly opening and closing the quick-opening valve at least five times. The applied vacuum load shall start at 0 kPa (0 psI), increase to 85 kPa (12 psi), and then decrease to o kPa (0 psi).
Note: 85 kPa (12 psi) is equivalent to 638 mm (25 in) of mercury
5.9.2.4 Test procedure for anti-siphon fill valves with check valves
When the specimen incorporates one or more check valves, the test procedure specified in Clause 5.9.2.3 shall be repeated with all check valves fouled in accordance with Clause 5.9.2.5.
5.9.2.5 Fouling
The check valves of the specimen shall be fouled using a 0.81 mm (0.032 in) diameter fouling wire. On check members that are hinged, the wire shall be placed in the 90° quadrant opposite to the hinge point or point of suspension. When a specimen in which the check members are not hinged but move axially is being tested, the wire shall be placed at a single point on the seating area. The fouling wire shall follow the contour of the valve seats.
When specimens have other types of moving parts for check members, those parts shall be spaced so that they comply with the intent of this Clause.
5.9.2.6 location of the critical level
5.9.2.6.1 CondItioning
With the specimen installed in accordance with Figure 6, and the overflow tube blocked and all check valves fouled in accordance with Clause 5.9.2.5, the specimen shall be submerged for at least 5 mm so that all of its openings and exterior and interior surfaces are thoroughly wetted.
5.9.2.6.2 Determination of the critical level
With the water level in the flush tank lowered to 3 mm (0.12 in) below the atmospheric vent(s) (in the case of a vacuum-breaker-type anti-siphon fill valve) or water discharge opening (in the case of an air-gap-type anti-siphon fill valve), a vacuum of 85 kPa (12 psi) shall be applied to the specimen while the water level in the flush tank is gradually lowered. The elevation at which back siphonage ceases (SB in Figure 6) shall be marked. A vacuum of 85 kPa (12 psi) shall then be applied to the specimen as the water level in the flush tank is gradually raised. The elevation at which back siphonage begins (AA in Figure 6) shall be marked. Whichever elevation is lower shall be the critical level.
85 kPa (12 psi) is equivalent to 638 mm (25 in) of mercury.CSA B125.3-2012 pdf free download.