12.2 Health Care Water Supply Protection, Water Services & Medical Gas

Health Care Water Supply Protection, Water Services & Medical Gas

Hospitals hold the most backflow hazards of any building type. Hoses rest in bedpan washers, aspirators connect to suction, laboratory faucets feed tubing, and equipment holds chemicals and body fluids, all on the same potable system that serves drinking fountains and patient sinks. The ICC P3 outline weights health care water supply protection at 3 percent. This section covers IPC 608.3.1 and 609.2 through 609.6, plus IPC Chapter 12 for medical gas.

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Backflow Protection for Hospital Fixtures (IPC 608.3.1)

IPC 608.3.1 requires the water supply for hospital fixtures to be protected against backflow by one of these:

1. A reduced pressure principle backflow prevention assembly (RPZ, ASSE 1013).
2. An atmospheric or spill-resistant vacuum breaker assembly.
3. An air gap.

The same section sets minimum heights for hose-connected vacuum breakers:

Measuring the Flood Level Rim for Hoses (IPC 609.4)

For hose connections, the flood level rim is the maximum height at which any hose is used. A hose lifted above a fixed vacuum breaker could siphon backward through it. Setting the vacuum breaker 6 inches above the highest point of hose use keeps the device above any liquid the hose could reach.

General Vacuum Breaker Rules (IPC 608.16.4)

• Atmospheric and pressure-type vacuum breakers have their critical level at least 6 inches above the flood level rim, and pipe-applied vacuum breakers are installed at least 6 inches above it.
• Deck-mounted or integral vacuum breakers have a critical level at least 1 inch above the flood level rim, per their listing.
• Vacuum breakers are not installed under exhaust hoods or similar locations with toxic fumes, so laboratory fume hood outlets need another type of protection.

       VACUUM BREAKER HEIGHT AT A HEALTH CARE HOSE OUTLET (609.4)

    ┌─ Vacuum breaker ──────────────────────┐
    │  At least 6 in above the highest point │
    │  of hose use (609.4)                   │
    └───────────────┬───────────────────────┘
                    │ 6 in min
    ─ ─ ─ ─ ─ ─ ─ ─ ┴ ─ ─ ─  Highest point the hose is used
                    │        (the "flood level rim" for hoses)
                  hose
                    │
    Floor ═════════════════════════════════════
      Health care/lab hose connections: vacuum breaker at least 6 ft
      above the floor; bedpan washer hoses at least 5 ft (608.3.1)

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Table 608.1 Devices Common in Health Care

Dental pumping equipment (IPC 608.17.9): The supply to each dental pumping system is protected by an air gap, RPZ, pressure vacuum breaker, atmospheric vacuum breaker or chemical dispenser backflow device (608.14.1, 608.14.2, 608.14.5, 608.14.6 or 608.14.8).

Clinical equipment (IPC 609.6): Clinical, hydrotherapeutic and radiological equipment supplied with water must meet Section 608.

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Redundant Water Services for Hospitals (IPC 609.2)

Group I-2, Condition 2 facilities (hospitals) need at least two water service pipes. They must be sized so that, if the largest service pipe is lost, the remaining services still meet the entire facility's water demand.

• Shutoff valves: Each service has a shutoff valve inside the building and another at the utility point of connection to the water main or other potable source.
• Tracer wire (IPC 609.2.1): Underground nonmetallic hospital water service piping needs an insulated tracer wire listed for the purpose (or another approved conductor) laid adjacent to the pipe. The wire is at least 18 AWG, with insulation suitable for direct burial. It must be accessible or end above ground at each end of the nonmetallic piping.

Worked check: A hospital's demand is 900 gpm. Two services rated 600 gpm each fail the rule, because losing either leaves 600 gpm. Two services rated 900 gpm each pass. So do three services rated 450 gpm each, because losing one leaves 900 gpm.

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Medical Gas, Vacuum and Oxygen Piping (IPC Chapter 12)

• Medical gas (IPC 1202.1): Nonflammable medical gas systems, inhalation anesthetic systems and vacuum piping systems are installed, tested and labeled per NFPA 99. The section does not apply to portable systems or cylinder storage. Vacuum exhaust terminations comply with the International Mechanical Code.
• Nonmedical oxygen (IPC 1203.1): Designed and installed per NFPA 51 and NFPA 55.
• Operations (IPC 1201.1): Maintenance and operation of these systems follow the International Fire Code.

The plans examiner confirms that the drawings reference NFPA 99 for medical gas zone valves, alarms and outlets, and that the piping is shown separately from potable water.

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Plan Reviewer Verification Checklist: Health Care Water Supply

• Fixture Protection: Hospital fixture supplies use an RPZ, atmospheric or spill-resistant vacuum breaker, or an air gap (608.3.1).
• Hose Heights: Bedpan washer hose vacuum breakers are at least 5 feet above the floor, and other health care or lab hose vacuum breakers at least 6 feet (608.3.1).
• Flood Rim Rule: Vacuum breakers are at least 6 inches above the highest point of hose use (609.4).
• Fume Hoods: No vacuum breakers are placed under exhaust hoods (608.16.4).
• Dual Services: I-2, Condition 2 hospitals have at least two services, each passing the largest-service-lost test, with valves at both ends (609.2).
• Tracer Wire: Nonmetallic underground services have at least 18 AWG direct-burial tracer wire (609.2.1).
• Medical Gas: Medical gas and vacuum piping references NFPA 99 (1202.1).