ASME A112.1002:2020 pdf free download – Anti-siphon fill valves for water closettanks
4.6.2.2.1 Test specimen installation set-uplnstallation set-up shall be conducted as follows:
a)For a device without a Cl mark, determine the critical level location according to the procedure inClause 4.6.2.3.
b)For a device with a CL mark, install the test specimen as shown in Figure 2.c)Foul all check members in accordance with Clause 4.6.2.1.2.
4.6.2.2.2 Procedure to determine if there are hidden checksTo determine if there are hidden checks, the following shall be conducted:a)Hold all check valves,seats, and checking members fully open.
b)Seal off the air inlet ports.
c) Assemble a sight glass to the shank assembly as shown in Figure 2.d)Submerge the test specimen completely under the water in the tank.e)Subject the test specimen to a vacuum of 85 ± 4 kPa (25.0 ± 1 inHg).f)Check for water in the sight glass.
g)Failure of water to appear in the sight glass shall indicate the presence of a hidden check valve.h)ldentify the hidden check(s) and repeat the procedure in Clause 4.6.2.2.2 with all check(s) fouled until water appears in the sight glass.
4.6.2.2.3 Procedure to evaluate backflow preventionEvaluating backflow prevention shall be conducted as follows:
a)Install the test specimen as shown in Figure 2, so that its critical level is 25 +0,-2.5 mm(1+0,-0.1 in) above the overflow tube.
b)The following loads shall be applied in sequence with the valve held fully open:
i)Apply and hold a vacuum (expressed in pressure below ambient) of 85± 4 kPa (25.0± 1 inHg) for 5 min ± 15 s.
ii)Observe for flow of water through the sight glass.
iii) Allow the pressure on the supply side of the specimen to return to atmospheric.
iv)Raise the vacuum gradually from 0 to 85 ± 4 kPa (0 to 25.0± 1 inHg) and then gradually reduce it to 0 kPa (0 inHg).
v)Observe for flow of water through the sight glass.
vi)Create a surge effect by rapidly opening and closing the quick-opening valve at least five times. Start at 0 kPa (0 inHg), increase the vacuum to 85± 4 kPa (25.0 ± 1 inHg), and decreaseto 0 kPa (0 inHg).
vii)Observe for flow of water through the sight glass.
4.6.2.3.2 Procedure to determine the critical level locationThe critical level location shall be determined as follows:
a)Lower the water level in the tank to 3.00±0.25 mm(0.12±0.01 in) below the
i)atmospheric vent(s), in the case of fill valves with vacuum-breakers; or
ii)water discharge opening, in the case of fill valves with air-gaps.
b)Apply a vacuum of 85 ±4 kPa (25.0 ± 1 inHg) to the specimen while the water level in the tank is gradually lowered at a rate of s 5 mm/30 s (o.2 in/30 s).
c)Record the elevation at which backsiphonage ceases (BB in Figure 3).
d)Lower the water level to 25 +0-2.5 mm (1 +0-0.1 in) below mark BB.
e) Apply a vacuum of 85±4 kPa (25.0 ± 1 inHg) to the specimen as the water level in the test tank is gradually raised at a rate of s 5 mm/30 s (0.2 in/30 s).
f) Record the elevation at which backsiphonage begins(AA in Figure 3).g)Determine the lower elevation (AA or BB) as the critical level.
h) lf water fails to appear in the sight glass, the device shall be installed as shown in Figure 2 and tested according to the procedure specified in Clause 4.6.2.2.2 and retested to meet the requirements of Clause 4.6.2.3.
4.6.2.3.3 Procedure to verify the CL mark
After completion of the procedure specified in Clause 4.6.2.3.2, the specimen shall be installed in thetank with the critical level located 25 +0-2.5 mm (1 +0-0.1 in) above the top of the overflow tube (seeFigure 3). Surge vacuum loading, as specified in Clause 4.6.2.2.3 b) vi), shall then be applied to verify thelocation of the critical level.