Gas Leak Equivalent Hole Diameter
The inverse of the gas-leak-rate tile: the equivalent orifice (hole) diameter from a measured leak rate, d = sqrt( 4 Q / (3550 c pi sqrt(dP / SG)) ). A 3.15 cfh natural-gas leak at 0.25 psi with c 0.7 is about a 0.050 in hole. Turns a clocked or metered leak into a hole size. An estimate of the effective hole, not a code leak-test method; any leak is a hazard - find and repair it. Uses the gas orifice-flow form (not the water orifice tile).
Formula and source
d = sqrt( 4 Q / (3550 x c x pi x sqrt(dP / SG)) ), the inverse of Q = 3550 x c x (pi d^2 / 4) x sqrt(dP / SG); orifice area A = Q / (3550 c sqrt(dP/SG)).
Classical orifice-flow leak approximation (compressible small leak), solved for the diameter; the 3550 coefficient and gas specific gravity from public engineering references.
Audience
This tile is built for plumbers and the adjacent professions in the Plumbing and Gas group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.
Related tools
Posture
Rough Logic answers the math question the working professional asks on the job. The site is a calm, fast, ad-free, account-free, ever-free reference. It does not interpret code. It does not replace the licensed professional. It does not store your inputs. The Authority Having Jurisdiction governs all installations and inspections.