Valve position and shut-off tags
A position tag tells whoever reaches the valve how it is meant to be left: NORMALLY OPEN, NORMALLY CLOSED, LOCKED OPEN. A shut-off tag tells them which valve to close in an emergency. Put the position on the bottom line of the numbered tag, or hang a tag of its own. Every tag below is ready to order and opens in the builder so you can change it.
Position tags
On a 3″ × 1½″ rectangle the position word engraves big enough to read across a mechanical room. The short forms fit a 2″ round.
Shut-off and do-not-operate tags
Shut-off tags carry the color of the service they shut off, so the gas shut-off is yellow and the water main is green. Do-not-operate tags are red.
Main water shut-off
Gas shut-off
Emergency gas shut-off
Fuel oil shut-off
Boiler isolation
Do not operate
Do not close
Emergency shut-off (octagon)
On the tag, or a tag of its own?
On the numbered tag. The bottom line of a valve tag is the usual place for the position: DCW / V-101 / N.O. One tag per valve, and the chart lists the same thing. Use the short forms N.O. and N.C. so the number stays big.
A tag of its own. Hang a separate position tag when the position matters more than the number — a valve that must stay closed, a balancing valve nobody should touch, a crossover between two systems. A word tag reads from further away than a bottom line.
Most jobs do both: the position on every numbered tag, and a separate tag on the handful of valves that would cause trouble if someone moved them.
Position abbreviations
Use the same ones on the tags, the valve chart and the drawings.
| On the tag | Means | Typical valves |
|---|---|---|
| N.O. | Normally open | Isolation valves on supply and return, sprinkler control valves |
| N.C. | Normally closed | Drains, bypasses, crossovers, standby equipment |
| L.O. | Locked open | Valves that must not be closed while the system runs |
| L.C. | Locked closed | Valves that must not be opened while the system runs |
| THROTTLED | Partly open, set during balancing | Balancing and circuit setter valves |
Locked means a lock. A LOCKED OPEN tag says how the valve is to be left; it doesn’t lock anything. Use a valve lockout device or a chain and padlock, and follow your lockout program (CSA Z460 in Canada, OSHA 29 CFR 1910.147 in the US).
How big do the words engrave?
Letter heights from the engine, for the tags above.
| Wording | Tag | Top line | Main line | Bottom line |
|---|---|---|---|---|
| NORMALLY / CLOSED | Rectangle 2½″ × 1¼″ | 9/32″ | 7/16″ | — |
| Rectangle 3″ × 1½″ | 11/32″ | 17/32″ | — | |
| Rectangle 4″ × 2″ | 7/16″ | 23/32″ | — | |
| MAIN WATER / SHUT-OFF | Rectangle 2½″ × 1¼″ | 1/4″ | 11/32″ | — |
| Rectangle 3″ × 1½″ | 5/16″ | 13/32″ | — | |
| Rectangle 4″ × 2″ | 7/16″ | 19/32″ | — | |
| BALANCING VALVE / DO NOT ADJUST | Rectangle 2½″ × 1¼″ | 3/16″ | 7/32″ | — |
| Rectangle 3″ × 1½″ | 7/32″ | 1/4″ | — | |
| Rectangle 4″ × 2″ | 5/16″ | 3/8″ | — |
Tag the valves that matter most
Add position and shut-off tags to the same order as your numbered valve tags.