4. SANITARY PLUMBING FULLY VENTED SYSTEM On completion of this module, the student should be able to: Design, install and develop bills of quantities for a fully vented modified system for commercial and industrial premises of over SIX (6) floor levels or more. Assessment Criteria 4.1 Describe and design fully vented sanitary plumbing systems for commercial and industrial premises to meet the requirements of the Building Code of Australia, Plumbing Code of Australia and AS/NZS 3500. 4.2 Describe, design, install and develop bills of quantities for fully vented modified sanitary plumbing systems for domestic, commercial and industrial premises to meet the requirements of the Building Code of Australia, Plumbing Code of Australia and AS/NZS 3500. 4.3 Interpret various designs of sanitary plumbing systems for commercial and industrial premises of over SIX (6) floor levels and develop bills of quantities for these designs. Assessment Method may include Written assessment based on assessment criteria. Practical activities based on assessment criteria. Designs based on assessment criteria. Assignment based on assessment criteria Section 4-1
4.1 Describe and design fully vented sanitary plumbing systems for commercial and industrial premises to meet the requirements of the Building Code of Australia, Plumbing Code of Australia and AS/NZS 3500. Fully Vented System Refer AS/NZS 3500.2 Section 7 The fully vented sanitary plumbing system (as shown in Figure 4.1) is a system comprising the ventilation of every individual fixture trap and floor waste gully` by means of a trap vent or air admittance valve. Trapped fixtures connected to a floor waste gully are not vented and the discharge pipe must be within the specified distance. The system also incorporates a relief vent/s (see AS/NZS 3500.2) and cross-relief vent/s (see Clause 7.5.5) or pressure attenuators in accordance with the fixture unit loadings as outlined within AS/NZS 3500.2 Tables 7.1 and 7.2. This system is very rarely used these days and you need to make an application to the local drainage authority for permission to install them. The following types of vent/s (or air admittance valves as per AS/NZS 3500.2) are used within the system to maintain a constant atmospheric pressure on the outlets of the trap water seals and the removal of foul odours and gases, preventing a build up of pressure or the creation of a vacuum. Stack Vent Header Vent Relief Vent Pressure attenuator Cross-relief Vent Terminal Vent Trap Vent Common Vent Branch Vent Air admittance valve Section 4-2
Terminal Vent Header Vent Stack Vent Stack Vent Fixture Discharge Pipe Group Vent Relief Vent Common Discharge Pipe Group Vent Common Discharge Pipe Fixture Discharge Pipe Trap Vent Fixture Discharge Pipe Common Vent Cross Vent Relief Vent Fixtures Back to Back Trap Vent Indirect Connected Fixture Stack Trap Vent FW Relief Vent Fixture Pair Fixture Discharge Pipe Gully Fixture Discharge Pipe Stack Branch Drain Sanitary Drainage Fig. 4.1 Fully Vented System Section 4-3
Fully Vented Modified System Refer AS/NZS 3500.2. This section outlines the design requirements and installation methods for the fully vented and fully vented modified systems of sanitary plumbing. Students are encouraged to read AS/NZS 3500.2 Section 7. A fully vent modified sanitary plumbing system differs from the Fully Vented System. Individual fixture trap vents or air admittance valves are omitted and two or more fixtures discharging to the same common graded discharge pipe or branch are vented by means of one or more group and or branch vent/s or air admittance valve/s as shown in figure 4.2. Every graded discharge pipe connected to the stack must be vented by at least one vent or air admittance valve except the uppermost branch to the stack providing it is within distance. The following types of vent/s (or air admittance valves as per AS/NZS 3500.2) are used within the system to maintain a constant atmospheric pressure on the outlets of the trap water seals and the removal of foul odours and gases, preventing a build up of pressure or the creation of a vacuum. Stack Vent Header Vent Relief Vent Pressure attenuator Cross-relief Vent Terminal Vent Trap Vent Common Vent Branch Vent Air admittance valve Sizing of Stack The size of the stack is determined by the fixture unit loading of all the fixtures connected to it and the developed length of its vent. Develop Length Refer AS/NZS 3500.2 The develop length of a stack vent is: a) for stacks with relief vents, the length of the relief vent; or b) for stacks without relief vents, the length of the stack vent and the stack to the point of connection of the lowest branch. Section 4-4
Terminal Vent Header Vent Stack Vent Stack Vent Fixture Discharge Pipe Group Vent Relief Vent Common Discharge Pipe Group Vent Common Discharge Pipe Fixture Discharge Pipe Trap Vent Fixture Discharge Pipe Common Vent Cross Vent Relief Vent Fixtures Back to Back Trap Vent Indirect Connected Fixture Stack Trap Vent FW Relief Vent Fixture Pair Fixture Discharge Pipe Gully Fixture Discharge Pipe Stack Branch Drain Sanitary Drainage Fig. 4.2 Fully Vented Modified System Section 4-5
METHOD OF CALCULATION FOR STACK SIZE a) Calculate the total number of fixture units from all fixtures connected to the stack as given within AS/NZS 3500.2 Table 6.1 b) Size the stack according to: i) Table 7.2 (a) for stacks of 4 or more floor levels; ii) Table 7.2 (b) for stacks three or fewer floor levels. Using AS/NZS3500.2 students are to complete the table below TABLE 7.2 MAXIMUM LOADING ON STACKS IN FIXTURE UNITS Size of stack DN Maximum loading per floor level Maximum loading per stack (a) Four or more floor levels 40 50 65 80 100 125 150 225 (b) Three or fewer floor levels 40 50 65 80 100 125 150 225 Section 4-6
Example: A stack five (5) storeys high has 30 water closets, 16 wall-hung urinals, 5 baths, 10 showers, 18 hand basins and 5 domestic kitchen sinks. Using AS/NZS3500.2 students are to complete the table below Fixture Number Fixture Units Sub Total Water Closets 30 Wall-hung urinals 16 Baths 5 Showers 10 Basins 18 Domestic Kitchen Sinks 5 Stack Total (F.U) = a) a total of F.U s are connected to the stack; b) determine if the stack is above four (4) floors Number of floors = c) using AS/NZS 3500.2 Table 7.2 (b) determine the size of the stack. Size of stack DN (a) Four or more floor levels 40 50 65 80 Maximum loading per floor level 4 9 14 20 Maximum loading per stack 16 36 56 80 125 150 225 250 600 1 750 1 000 2 400 7 000 Note: The maximum fixture unit loading per floor is not to be exceeded. Refer AS/.NZS 3500.2. Four (4) floors or more = 25% of stack loading. Three (3) floors of less = 33% of stack loading. Where the fixture unit loading at any one floor level exceeds the maximum loading permitted in Table 7.2 (a) or Table 7.2 (b), the stack shall be increased in size. Section 4-7
Where a DN 80 stack is installed as a fully vented modified system, the maximum number of water closet pans and slop hoppers connected to any graded pipe or branch shall not exceed two. Student Exercise No 1 Students are required to size the stack shown in schematic view below; flush valves operate all water closet pans. Fig. 4.3 Student Exercise Second floor fixture unit loading First floor fixture unit loading Total Stack Size = DN Section 4-8
Student Exercise No 2 Students are required to size the stack shown in schematic view below, all water closet pans are cistern flush. S B B B 5th Floor FW WC WC WC S B B B B 4th Floor WC WC WC WC FW S B B 3rd Floor WC WC FW WC WC WC WC B 2nd Floor FW FW CS Shr Shr Shr Shr B B B 1st Floor Shr Shr wc wc wc wc wc wc Fig. 4.4 Student Exercise Fixture unit loading Stack Size = DN Section 4-9
Student Exercise No 3 Students are required to size the stack shown in schematic view below, all water closet pans are cistern flush. B B B B S 3rd Floor FW WC WC WC S B B B 2nd Floor FW WC WC WC B Bth FW Shr WC WC 1st Floor Fig. 4.5 Student Exercise Fixture unit loading Stack Size = DN Section 4-10
SIZING FIXTURE DISCHARGE PIPES As covered within Learning Outcome 7, fixture discharge pipes are sized from AS/NZS 3500.2 Table 6.1 (Fixture Unit Ratings). The sizing of graded discharge pipes to one fixture is determined from AS/NZS 3500.2 Table 6.1 (Fixture Unit Ratings) and must not be smaller than the trap to which they are connected, except in the case of water closet pans and slop hoppers, which may be connected to DN 80 common (graded) discharge pipes. Only two water closet pans shall be connected to any DN 80 discharge pipe. COMMON (GRADED) DISCHARGE PIPES The sizing of common (graded) discharge pipes connecting two or more fixture discharge pipes must not be smaller than the trap to which they are connected, except in the case of water closet pans and slop hoppers, which may be connected to DN 80 discharge pipes. It may vary in size along its length and is sized taking into account: a) the sum of the fixture units that it carries (see Table 6.1 and 6.2); and b) the proposed pipe grade. Using AS/NZS3500.2 students are to complete the table below TABLE 6.3 MINIMUM GRADES OF DISCHARGE PIPES Size of graded section of pipes Minimum grade DN % 40 50 65 80 100 125 150 225 300 Section 4-11
TABLE 7.1 MAXIMUM FIXTURE UNIT LOADINGS FOR GRADED DISCHARGE PIPES Grade Nominal size of pipe, DN % 40 50 65 80 100 125 150 225 5.00 3.35 2.50 6 5 4 15 10 8 51 29 21 65 39 27 376 248 182 953 686 509 1 959 1 445 1 148 7 098 5 583 4 513 2.00 1.65 1.25 X X X X X X X X X 20 16 X 142 115 X 410 342 254 953 813 627 3 739 3 258 2 656 1.00 X X X X X X 509 2 272 Note X = means not permitted CONNECTION TO COMMON DISCHARGE PIE Refer AS/NZS 3500.2. (b) (c) Graded discharge pipes of different sizes shall be connected so that the soffits of both pipes are in common alignment. The invert level of a trap or floor waste gully weir shall be a minimum of 10 mm higher than the soffit of the graded discharge pipe to which it connects (see Figure 6.2. DN 65 SOFFIT DN 50 DN 40 Fig. 4.6 Soffit (common) alignment of pipes Section 4-12
Example: A common (graded) discharge pipe has 5 water closets (cistern flush), 1 x 2.6 m urinal, 1 cleaners sink, 1 shower, 2 hand basins and 1 domestic kitchen sink; the pipes are to be graded as per Table 6.3. Fig. 4.7 Example Section 4-13
Student Exercise No 4 Students are required to SIZE the common (graded) discharge pipes as shown in schematic view below, all water closet pans are CISTERN FLUSH. Fig. 4.8 Student Exercise Section 4-14
Student Exercise No 5 Students are required to SIZE the common (graded) discharge pipes as shown in schematic view below, all water closet pans are CISTERN FLUSH. Fig. 4.9 Student Exercise Section 4-15
Student Exercise No 6 Students are required to size the common (graded) discharge pipes as shown in schematic view below, all water closet pans are cistern flush. Fig. 4.10 Student Exercise Section 4-16
STACK VENT Refer AS/NZS 3500.2. A stack vent is the continuation of the stack above the highest branch; it may extend separately to atmosphere or interconnect with the relief vent above the overflow level of the highest fixture connected. Stack and Relief vents are sized using AS/NZS 3500.2 Table 7.5 and the following: a) the sum of the fixture units that discharge into the stack (see Table 6.1 and 6.2); and b) the size of the stack. c) the developed length of the vent The developed length of a stack vent is: for stacks with relief vents, the length of the relief vent; or for stacks without relief vents, the length of the stack vent and the stack to the point of connection of the lowest branch. Section 4-17
Size of stack Maximum fixture units connected TABLE 7.5 SIZE OF RELIEF VENTS AND STACK VENTS Maximum develop length of vent, m Required vent size, DN DN 32 40 50 65 80 100 125 150 40 50 50 16 20 36 6 8 6 15 15 10 46 30 65 65 80 80 20 56 20 80 12 7 8 40 24 27 12 110 80 70 20 170 110 100 100 100 150 300 500 9 8 6 25 22 19 70 60 50 280 216 197 125 125 125 300 750 1 100 9 7 6 22 19 14 95 72 62 280 230 190 150 150 150 700 1 300 2 400 4 9 7 6 37 30 24 155 130 100 300 250 200 225 225 225 1 700 4 000 7 000 16 14 6 62 43 31 RELIEF VENT Refer AS/NZS 3500.2. A relief vent is used to relieve pressure and/or vacuum conditions within the stack. It is usually fitted adjacent to the stack and they are required where: a) One or more floors separate the floor levels of the highest and lowest branch pipes connected (see Fig 4.11). c) For stacks with offsets, if disregarding the offset, one or more floors separate the floor levels of the highest and lowest branch pipes connected d) (see Fig 4.11). Section 4-18
It connects with the stack below the lowest fixture, at an angle of 45 and extends upwards at a minimum grade of 1.25%, interconnecting with the stack vent above the spill level of the highest fixture, or extending to open air and terminating in accordance with Clause 6.8.4. Stack and relief vent/s may also interconnect at their upmost point into a common header vent terminating at one point. The sizing of the relief vent is the same as for the sizing of stack vents using AS/NZS 3500.2 Table 7.5 Alternative relief vent terminates separately Alternative relief vent terminates separately Relief vent interconnecting with stack vent above highest fixture overflow level Stack vent Stack vent Min. grade 1.25% Highest connection Min. grade 1.25% Highest connection Relief vent Stack Alternative arrangement for relief vent Lowest connection 45 connection Lowest connection Relief vent required on lower vertical section of stack only 45 connection Fig. 4.11 Relief Vent installation for straight stacks Section 4-19
Alternative relief vent terminates separately Stack vent Min. grade 1.25% Relief vent required on both vertical of stack Aternative arrangement for relief vent 45 connection Relief vent required on both vertical of stack 45 connection Fig. 4.12 Relief Vent installation for graded offsets PRESSURE ATTENUATORS Pressure attenuators may be used in sanitary plumbing systems as an alternative to relief venting. Attenuators are used to counter the tendency for the loss of trap water seals resulting from positive pressure pulses in discharge stacks. Positive pressure pulses or transients arise from disruptions to airflow produced at changes in direction or restriction to the airflow path. The size of the pressure attenuator is independent of stack size and fixture unit loading the manufactures advice may need to be obtained. Installation requirements Pressure attenuators shall be (a) connected to stacks by means of 45 or sweep junctions; (b) positioned above the point of connection in either a vertical or horizontal orientation and Section 4-20
(c) adequately supported with allowance for thermal movement. Connections to the stack, other than those immediately above the base of the stack or offset, shall be above the branch discharge pipes at that floor level Fig. 4.13 Typical connection of pressure attenuators to stacks Fig. 4.14 Examples of typical pressure attenuators installation Students are encouraged to read AS/NZS3500.2 to obtain a fuller understanding of the installation for pressure attenuators Section 4-21
HEADER VENTS Refer AS/NZS 3500.2. A header vent may be used to interconnect the tops of two or more stack or relief vents, allowing a single vent termination. This is used to reduce the number of penetrations through the roof. SIZING Header vents are sized in accordance with the following: a) determine the number of DN 50 vents that are equivalent to each individual stack or relief vent/s interconnecting with the header vent, using AS/NZS 3500.2 Table 7.6. b) add together all such numbers c) note from Table 7.6 the size of a single equivalent header vent. d) where a stack has a relief vent, take into account the relief vent size only. e) any change in size of the graded header vent is made downstream and adjacent to the junction. f) header vents need not be larger than DN 300. Using AS/NZS3500.2 students are to complete the table below Size of stack vent or relief vent DN 50 65 80 100 125 150 250 300 TABLE 7.6 SIZE OF HEADER VENTS Equivalent number of DN 50 vents Size of header vent DN Section 4-22
Header vent Terminal vent Stach vent Stach vent Stach vent Stach vent Relief vent Relief vent Relief vent Relief vent Fig. 4.15 Header Vent Section 4-23
Student Exercise No 7 Students are required to size the header vent as shown in schematic view below, the stack is a fully vented modified system with a develop length of 20 m. Fig. 4.16 Student Exercise Section Number of DN 50 equivalents A B B C C D D - E Header vent size DN Section 4-24
CROSS-RELIEF VENTS Cross-relief vents are required on any stack that extends 20 or more floors in height. Cross-relief vents must be evenly spaced so that the intervals do not exceed 10 floor levels. Cross-relief vents connect to the stack at an angle of 45 below the lowest branch connecting to the stack at the floor concerned and connect with the relief vent above the flood level rim of the lowest fixture, discharging into the stack at that floor. The cross-relief vents are to be the same size as the relief vent or stack vent which ever is the smaller. Relief vent Stack Min. grade 1.25% Trap vent or air admittance valve Min. grade 1.25% Trap vent or air admittance valve S B B FW Cross-relief vent 45 connection Fig. 4.17 Installation of Cross-Relief Vent Section 4-25
20th Floor Highest graded pipe or branch connection to stack 19th Floor 18th Floor 17th Floor 16th Floor Max.10th floor level between Cross-relief vents 15th Floor 14th Floor 13th Floor 12th Floor 11th Floor Cross-relief vent 10th Floor Trap vent or air admittance valve Cross-relief vent not required untill stack exceeds 20 floor levels 9th Floor 45 connection 8th Floor 7th Floor 6th Floor 5th Floor 4th Floor 3rd Floor 2nd Floor 1 st Floor Group vent or air admittance valve 45 connection Sanitary Drain Fig. 4.18 Installation of Cross-Relief Vent Section 4-26
STACK OFFSETS STEEP Refer AS/NZS 3500.2 Clause 7.6.1 A steep offset has angles more than 45 to the horizontal and is considered to be a STRAIGHT STACK. The stack is sized using AS/NZS 3500.2 Table 7.2 (a) and (b). Only one (1) relief vent is required, there is no need to provide a relief for the section of stack below the offset and another for the section above. Stack vent Min. grade 1.25% Alternative arrangement for relief vent Angle more than 45 45 connection Fig. 4.19 Steep offset Section 4-27
GRADED Refer AS/NZS 3500.2. A stack offset is considered to be graded if its angle is less than 45 to the horizontal. Alternative relief vent terminates separately Stack vent Min. grade 1.25% Relief vent required on both vertical of stack Aternative arrangement for relief vent 45 connection Relief vent required on both vertical of stack 45 connection Fig. 4.20 Graded offset Section 4-28
MINIMUM GRADE Refer AS/NZS 3500.2 Table 7.8 The minimum grade of a graded offset shall be: Using AS/NZS3500.2 students are to complete the table below TABLE 7.8 MINIMUM GRADE OF OFFSET Size of grade section Min. gradient DN % <80 100 125 150 225 300 0.60 0.40 SIZING a) the entire stack must firstly be sized as if straight using AS/NZS 3500.2 Table 7.2 (a) or (b). b) the graded offset section is sized as a graded discharge pipe using AS/NZS 3500.2 Table 7.1; only consider the fixture units above the offset. The grade of the offset as given in Table 7.8 above and has to be considered. c) the size of the entire stack taken from the drainage connection point to above the highest connection is then taken to be whichever is the larger size, (a) or (b) above. The stack and relief vents are sized from AS/NZS 3500.2 Table 7.5. CONNECTION ABOVE A GRADED OFFSET No connection shall be made: a) within 600 mm of the upper bend for stacks not exceeding five (5) floors above the offset; b) within 1 m of the upper bend for stacks exceeding five (5) floors above the offset; c) within 2.5 m, when foaming is likely to occur. Section 4-29
CPCPSN4011A CONNECTION WITHIN A GRADED OFFSETS No connection shall be made: a) within 2.5 m of the upper bend; and b) within 450 mm of the lower bend. CONNECTION BELOW A GRADED OFFSETS No connection shall be made: a) within 600 mm of the lower bend. 3rd Floor 2nd Floor Alternative connection for above graded offset 600 mm (5 or less floors) 1 m (6 or more floors) 1st Floor Alternative connection for lowest branch No connection within this zone 2500 mm min. 600 mm min. No connection within this zone 450 mm min. Fig. 4.21 Connection within offset area Section 4-30
Student Exercise No 8 Students are required to size the stack, graded section, relief vent and stack vent as shown in schematic view below: all water closet pans are cistern flush; the stack has a develop length of 18 m; Fig. 4.22 Student Exercise Fixture Unit loading Stack vent Relief vent Stack Graded Offset DN DN DN DN Section 4-31
VENTING OF COMMON (GRADED) DISCHARGE PIPES The following vents are used to eliminate pressure build up and vacuum conditions within graded discharge pipes for the prevention of loss of water seal/s. TRAP VENT Trap vents are used to vent an individual trap to open air or interconnect with a branch vent, relief vent or stack vent. Air admittance may be used instead of a trap vent as outlined within AS/NZS 3500.2. Every trap vent shall be extended upwards to a point above the flood level rim of the fixture before interconnecting with another vent. Relief vent Stack Trap vent or air admittance valve Trap vent or air admittance valve 100 mm min rise Min. 100 mm rise INSERT N.T.S Fig. 4.23 Trap Vent Trap vents are sized off the fixture discharge trap and pipe to which they are connected: TABLE 7.3 MINIMUM SIZE OF TRAP VENTS Size of fixture trap Size of trap vent DN DN 40 32 <50 to <100 40 Section 4-32
GROUP VENT A group vent is connected to common (graded) discharge pipe, venting a group of fixtures. One group vent is required for each 10 fixtures, or part thereof, in any group connected to a common discharge pipe. The first group vent is connected up stream in the same location as for a trap vent or common vent, if other group vents are required they shall be connected to the common discharge pipe at approximately equal distances, so as no group vent serves more than ten (10) fixture branches or part there of. Group vents are sized off the common discharge pipes they serve. If the common discharge pipe varies in size, the group vent shall be sized off the largest section of the common discharge pipe they serve. At no time shall the group vent be larger than the common discharge pipe, if this occurs increase the common discharge pipe to the same size as the vent. Using AS/NZS3500.2 complete the table below Size of common discharge pipe DN 40 50 65 80 100 TABLE 7.7 SIZE GROUP VENTS Size of single group vent DN Common (graded) discharge pipes may have a vertical dropper not exceeding 1.5 m. Where such a dropper is used and there are fixtures connected to the downstream section a group vent must be provided. i) from the top of the vertical drop ii) iii) between the vertical drop and the first downstream fixture discharge pipe from the first downstream fixture discharge pipe Section 4-33
Vent interconnection above flood level rim of highest fixture connected to common graded discharge pipe B Group vent B Discharge pipe increased from DN 40-50 to service the vent S S Branch Vent Drop 1500 mm max. Group venting of vertical dropper alternative positions Venting of discharge pipe due to over distance or more than one fixture discharge pipe connected Vent connection within 1.5 m from weir of trap WC Air admittance valves may be used to replace trap or group vents. Refer AS/NZS 3500.2 Clause 6.9 Min. grade 1.25% Vent connection within 600 mm for a basin/bidet and 1.5 m for other fixtures from weir of trap Group vent alternative positions Fig. 4.24 Venting of Common Discharge Pipe Connecting vents to a graded or common discharge pipe When connecting a vent or Air Admittance Valve (AAV) to a graded or common discharge pipe, it must meet the requirements of AS/NZS 3500.2. a) In the case of basins and bidets, the vent/aav shall be connected no closer than 75 mm and no further than 600 mm from the crown of the fixture trap, provided no change of direction occurs between the trap and the vent/aav. b) In the case of fixtures other than basins and bidets, the vent/aav shall be connected between 75 mm and 1.5 m, provided that where an S-trap or a bend is fitted downstream of a P-trap, the vent/aav connected on the vertical discharge pipe shall be at least 300 mm from any bend at the base of the vertical section. Section 4-34
No connections permitted within this distance P-trap or S-trap 75 mm 600 mm for basins/bidets 1.5 m for other fixtures A No connections permitted within this distance 300 mm min. 1.5 m max. 75 mm no connections permitted within this distance Connect vent/aav within this length B Fig. 4.25 BRANCH VENT Connect vent/aav within either Section A or B Connection of vents/aav to Graded or Common Discharge Pipes A branch vent may interconnect with the relief or stack vent or may extend to open air and terminate in accordance with the requirements of AS/NZS 3500. The point of interconnection between a branch vent and any other vent connected to a graded or common discharge pipe is above the flood level rim of the highest fixture connected to the graded or common discharge pipe. Using AS/NZS3500.2 students are to complete the table below TABLE 7.4 MINIMUM SIZE OF BRANCH VENTS Size of branch discharge pipe Size of branch vent DN DN 40 50 65 80 100 150 Section 4-35
Student Exercise No 10 Students are required to complete the design showing the position, type and size of vents required for the system shown in schematic view below, all water closet pans are cistern flush. Fig. 4.26 Student Exercise Section 4-36
Student Exercise No 11 Students are required to complete the design showing the position, type and size of vents required for the system shown in schematic view below, all water closet pans are cistern flush. Fig. 4.27 Student Exercise Section 4-37
Student Exercise No 12 Students are required to complete the design showing the position and capacity of air admittance valves (trap and group vents only) for the system shown in schematic view below, all water closet pans are cistern flush. Fig. 4.28 Student Exercise Section 4-38
Student Exercise No 13 Students are required to complete the design showing the position and capacity of air admittance valves (trap and group vents only) for the system shown in schematic view below, all water closet pans are cistern flush. Fig. 4.29 Student Exercise Section 4-39