High Rise Water Systems

Question 1

Class 1 Water System

Answer 1

Dry Standpipe

Required in: older (pre-60) high rises 4+ stories, (60-74) 4+ stories and < 150’, (74+) 4+ stories and <150’

Question 2

Class II Water System

Answer 2

(Wet) Standpipe system

Required in: 3+ stories and directly connected to water supplied hose cabinets

Question 3

Class III water system

Answer 3

Combination standpipe system (I+II in same riser)

Found in 60-74

Question 4

Combined water system

Answer 4

Combined sprinkler- standpipe system
Required in (74+) buildings > 150’
Directly connected to water supply w/ 2 1/2’’ outlets

Question 5

Building under 150’

Answer 5

Question 6

Buildings 150’ +

Answer 6

Question 7

C.O.P.S.I.O.
Buildings < 150’ 
Pre- 60’
1960- 1974
1974- present (<75’)

Answer 7

Class— I (Dry) Standpipe (FD use) 4+ stories
II (Wet) Standpipe (occupant use) 3+ stories
On- site water— domestic fed, DWP supplied
Pump— none
Sprinklers— basements only
Inlets— (2) 2 1/2’’ if 4-5 stories, (4) 2 1/2’’ if 6+ stories
Outlets— 2 1/2’’ gate or globe valve on Ext fire escape
(60-74’) 2 1/2’’ outlets moved to stairwells

Question 8

C.O.P.S.I.O.
Buildings > 150’
1960- 1974

Answer 8

Class— III (combination Standpipe)- directly connected to water
II (wet) standpipe- 2 1/2’’ outlets w/ 1 1/2’’ reducer + 100’ of 1 1/2’’ hose/ nozzle for occupant use. 5+ floors— 2 1/2’’ outlet w/ 100’ 2 1/2’’ hose w/ 1’’ tip for FD use
On- site water— domestic, augmented
Pump— diesel or electric, jockey pump to maintain static pressure
Sprinkler— required in basements, supplied by domestic water
Inlets— (4) 2 1/2’’, supply 1000 gpms
Outlets— 2 1/2’’ in stairwells w/ orifice plates
Possible 2 1/2’’ hose cabinets w/ 1’’ tip on 5th+ floors w/ PRV’s

Question 9

C.O.P.S.I.O.
Buildings <150’
1974- present (75-150’)

Answer 9

*considered a high rise
Sprinklered—> wet hose cabinets for occupant use no longer required, 2 1/2’’ hose removed from cabinets
Class— I (dry) standpipe: water supplied for sprinklers (DAMP), must be augmented by FD
On- site water— domestic fed sprinklers, FD must augment to flow water (limited to 30 mins +100 gpm for SP)
Pumps— fire pump
Sprinklers— fully sprinklered
Inlets— 100 GPM/ riser (4) 2 1/2’’ inlets
Outlets— (2) 2 1/2’’ w/ orifice plates or PRVs