10.3 Shutoff Valves, Drips, Unions, Sediment Traps & Appliance Connectors

10.3 Shutoff Valves, Drips, Unions, Sediment Traps & Appliance Connectors

Quick Answer: IFGC 2018 Section 409.5.1 requires the appliance shutoff valve to be in the same room as the appliance, within 6 feet of it, installed upstream of the union, connector or quick-disconnect device it serves, and provided with access.

Section 409 (shutoff valves), Section 408 (drips and sediment traps) and Section 411 (appliance connections) are the three parts of IFGC Chapter 4 that a plumbing inspector checks on literally every gas appliance installation, which is why they are so heavily represented in the 40-question Gas Appliances and Piping domain. Every rule below is a location, a distance or a fitting type — the exact material multiple-choice questions are built from.

Where Shutoff Valves Go

Three limits apply to every valve in that list. Under 409.1.2, shutoff valves are prohibited in concealed locations and in furnace plenums. Under 409.1.3, they must be located so as to provide access for operation and be protected from damage. Under 409.7, a valve installed in a tubing system must be rigidly and securely supported independently of the tubing, because operating torque on a ball valve handle would otherwise be transmitted straight into soft tube and work-harden or kink it.

Two accessibility nuances trip candidates. First, a valve behind a movable appliance — a range or a clothes dryer — is considered to be provided with access under 409.5.1; you do not need a wall access panel for a dryer valve. Second, "access" (reachable, possibly after removing a panel) is a weaker standard than "ready access" (reachable without removing a panel, door or obstruction and without using a portable ladder), and 409.5.2 and 409.5.3 demand ready access precisely because those valves are remote from the appliance they control.

Where 409.5.2 or 409.5.3 puts the valve away from the appliance, the piping from that valve or manifold to within 6 feet of the appliance must still be designed, sized and installed under Sections 401 through 408 — the remote-valve allowance relaxes the valve location, not the piping standard. Valve approval (409.1.1, Table 409.1.1) is pressure-keyed: ANSI Z21.15/CGA 9.1 valves are limited to the appliance shutoff application up to 1/2 psig; ASME B16.44 valves cover the appliance shutoff application and other applications up to 1/2 psig, up to 2 psig where labeled 2G, and up to 5 psig where labeled 5G; ASME B16.33 valves cover every column, up to 125 psig.

Slopes and Drips (408.1–408.3)

Dry gas is fuel gas delivered with essentially no entrained moisture. Almost all utility-distributed natural gas is dry, which is why most residential jobs never involve a drip at all. Where the gas is wet gas — carrying moisture or heavy hydrocarbons that can condense in the line — three rules kick in:

• 408.1 Slopes. Piping for other than dry gas conditions shall be sloped not less than 1/4 inch in 15 feet so condensate runs to a collection point instead of forming liquid traps that throttle the line.
• 408.2 Drips. Where wet gas exists, a drip shall be provided at any point in the line where condensate could collect, and a drip shall be provided at the outlet of the meter. The meter drip must be installed so as to constitute a trap in which accumulating condensate shuts off the flow of gas before the condensate can run back into the meter.
• 408.3 Location of drips. Drips shall be provided with ready access to permit cleaning or emptying, and a drip shall not be located where the condensate is subject to freezing — no unheated crawl space, no exterior wall cavity, no attic in a Maryland January.

Worked Example — Fall on a Wet-Gas Run

A 90-foot horizontal wet-gas run pitched at the code minimum: 90 ÷ 15 = 6 fifteen-foot increments, and 6 × 1/4 inch = 1-1/2 inches of total fall from the high end down to the drip. Per foot that is 0.25 ÷ 15 = 0.0167 inch per foot — roughly 1/64 inch per foot, a far gentler pitch than the 1/4 inch per foot used for small sanitary drainage. Reading "1/4 inch in 15 feet" as "1/4 inch per foot" is an easy unit slip after a morning of IPC drainage tables, and it produces an answer 15 times too large.

Sediment Traps (408.4)

A sediment trap — called a drip leg on most job sites — catches rust, scale and mill debris before it reaches an appliance's gas valve and burner orifices. IFGC 2018 Section 408.4 answers three questions:

1. When. Wherever a sediment trap is not incorporated as part of the appliance.
2. Where. Downstream of the appliance shutoff valve, and as close to the inlet of the appliance as practical. Placing it upstream of the valve is the classic wrong answer — you would then have to shut the whole branch down to service the trap.
3. What. A tee fitting with a capped nipple of any length installed vertically in the bottommost opening of the tee (Figure 408.4), or another device approved as an effective sediment trap. Gas travels through the run of the tee; debris falls into the capped leg. The code sets no minimum nipple length, so a short capped nipple is compliant as long as it points down.

Where a Sediment Trap Is and Is Not Required

The exempt list in IFGC 2018 Section 408.4 is exactly six items: illuminating appliances, ranges, clothes dryers, decorative vented appliances for installation in vented fireplaces, gas fireplaces and outdoor grills. NFPA 54 (2018) Section 9.6.8 carries the identical list, wording the last item "outdoor cooking appliances." Anything not on that list — and a water heater and a furnace are the two the exam asks about most — gets a trap.

Unions (411.1.6)

An appliance connected by rigid metallic pipe must be provided with a union fitting, and that union shall be accessible and located within 6 feet of the appliance. The union is what lets a technician break the appliance loose without cutting pipe. Read it together with two other sections: 409.5.1 puts the shutoff valve upstream of the union, so closing the valve isolates the joint you are about to open; and 404.5's permitted-fitting list does not include unions, so a union may never be left in a concealed wall, floor or ceiling cavity. Union, valve and sediment trap all belong in the same accessible pocket of pipe at the appliance.

Appliance Connectors (411.1)

Section 411.1 permits nine ways to connect an appliance, of which four carry the numbers most often tested: rigid metallic pipe and fittings; CSST installed per the manufacturer's instructions; semirigid metallic tubing with metallic fittings, limited to 6 feet and located entirely in the same room as the appliance; and listed and labeled appliance connectors complying with ANSI Z21.24/CGA 6.10, also located entirely in the same room. Listed quick-disconnect devices, listed gas convenience outlets, listed outdoor appliance connectors (ANSI Z21.75/CSA 6.27), listed outdoor gas hose connectors (ANSI Z21.54) for portable outdoor appliances, and laboratory hose connectors round out the list. Commercial cooking appliances on casters get their own rule: 411.1.1 requires a connector listed to ANSI Z21.69/CSA 6.16 plus a restraining device limiting appliance movement.

Exam Trap: The most commonly missed number here is connector length. Older fuel gas code editions limited connectors to 3 feet, with 6 feet allowed only for ranges and domestic clothes dryers, and that pair of numbers is still printed across a lot of trade study material and on connector packaging. IFGC 2018 Section 411.1.3.1 has one number: 6 feet, for every appliance, measured along the centerline — and only one connector may be used for each appliance. On an exam keyed to the 2018 edition, "3 feet, except 6 feet for ranges and dryers" is the trap answer, and coupling two connectors together to reach 10 feet is the trap installation.

Connector Installation Rules (411.1.2–411.1.3.4)

Four exceptions soften the no-penetration rule of 411.1.3.3: connectors built of Section 403 piping materials may pass through building elements where installed per 409.5.2 or 409.5.3; rigid steel pipe connectors may extend through openings in appliance housings; fireplace inserts factory-equipped with grommets or sleeves are permitted; and semirigid tubing or listed connectors may extend through an opening in an appliance housing, cabinet or casing where protected against damage. Related: semirigid metallic tubing shall not enter a motor-operated appliance through an unprotected knockout opening — the sheared edge of a knockout will saw through soft tube under vibration.

Reusing a connector. The IFGC does not print the sentence "do not reuse a connector," but two provisions get you there. Section 403.2 permits pipe, fittings and valves to be used again only where they are free of foreign materials and have been ascertained to be adequate for the service intended, and 411.1.3 requires connectors to be installed in accordance with the manufacturer's instructions — and those instructions uniformly prohibit reinstalling a used connector, because the soft sealing surfaces of the ball-and-cone ends deform permanently on first make-up. Older uncoated brass connectors have been the subject of long-running replacement campaigns for exactly this failure mode. Cut the old one out and install a new listed connector.

Quick-Disconnect Devices and Convenience Outlets

The IFGC defines a quick-disconnect device as a hand-operated device that provides a means for connecting and disconnecting an appliance or appliance connector to a gas supply and that is equipped with an automatic means to shut off the gas supply when the device is separated. That automatic shutoff is the whole point of the device and is the exam's favorite one-line answer. NFPA 54 (2018) 9.6.6.1 requires these devices to be listed to ANSI Z21.41/CSA 6.9, and 9.6.6.2 requires an approved manual shutoff valve with a nondisplaceable valve member upstream of an indoor quick-disconnect device. Listed gas convenience outlets (ANSI Z21.90/CSA 6.24) do the same job behind a wall plate.

These two devices are also the exception to the capping rule: Section 404.15 requires gas outlets that do not connect to an appliance to be capped gas tight, except for listed and labeled flush-mounted quick-disconnect devices and listed gas convenience outlets installed per the manufacturer's instructions.

CSST and Appliance Connectors

CSST is a piping system material, not an appliance connector. It may connect an appliance directly under 411.1 Item 2 when installed in accordance with the manufacturer's instructions and its listing (404.2), but that changes none of the other requirements: the appliance still needs its 409.5 shutoff valve, its 408.4 sediment trap where not exempt, and its 411.1.6 union if the final connection is rigid pipe. CSST support spacing comes from the manufacturer's instructions rather than Table 415.1, and Section 310.2 requires non-arc-resistant CSST systems to be bonded to the electrical service grounding electrode system with a jumper not smaller than 6 AWG copper (310.2.2). What you may not do is splice a listed flexible connector onto a run of CSST to gain reach — the 6-foot, one-connector-per-appliance limit of 411.1.3.1 still governs the connector itself.