# COMAR Title 09 — Maryland Department of Labor

## Subtitle 12 — Division of Labor and Industry

### Chapter 01 — Board of Boiler Rules

#### Regulation .20 Power Boiler — Existing Installation: Age Limit.

*COMAR 09.12.01.20*

A. Nonstandard Construction.

  (1) Except as otherwise provided in this regulation, the age limit of a boiler of nonstandard construction installed before the Act became effective shall be 30 years.

  (2) A boiler of nonstandard construction installed before the Act became effective, not having a lap-riveted longitudinal joint, may continue to operate for more than 30 years without reduction in working pressure after a:

    (a) Thorough internal and external inspection; and

    (b) Hydrostatic pressure test at 1-1/2 times the allowable working pressure, held for a period of at least 30 minutes, during which no distress or leakage develops.

  (3) A boiler having a lap-riveted longitudinal joint, which operates at a pressure greater than 50 PSI, has an age limit of 20 years.

  (4) The chief boiler inspector may authorize a reasonable time for replacement, not to exceed 1 year.

B. Standard Construction.

  (1) The age limit of a boiler of standard construction installed before July 1, 1969 shall be determined by a:

    (a) Thorough internal and external inspection; and

    (b) Hydrostatic pressure test conducted at 1-1/2 times the maximum allowable working pressure, with water temperature between 70°F and 140°F and not less than the nil ductility temperature of the material.

  (2) A boiler that exhibits no distress or leakage under test conditions may continue in operation at the same working pressure.

C. The shell or drum of a boiler having a lap-seam crack along a longitudinal riveted joint in either a butt seam or a lap joint may not be used under steam pressure.