# COMAR Title 09 — Maryland Department of Labor

## Subtitle 12 — Division of Labor and Industry

### Chapter 01 — Board of Boiler Rules

#### Regulation .30 Stamping.

*COMAR 09.12.01.30*

A. At the first post-installation internal or certificate inspection, the inspector shall assign to a boiler or pressure vessel a Maryland serial number that is:

  (1) At least 5/16 of an inch in height;

  (2) Configured as follows:

    (a) For power boilers	<MD>	MD 0000;

    (b) For heating boilers	<MD>	MD 0000H;

    (c) For pressure vessels	<MD>	MD 0000V;

    (d) For nuclear vessels	<MD>	MD 0000N; and

  (3) Stamped on:

    (a) The boiler or pressure vessel, or

    (b) A metal tag at least 1 inch in height, securely attached to the front of:

      (i) A low pressure heating boiler constructed of cast iron, or

      (ii) A pressure vessel constructed of cast iron or other material of a thickness that should not be stamped.

B. Unless a record is kept showing the location of stamping so that the stamping can be uncovered readily, stamping:

  (1) May not be concealed by lagging or paint; and

  (2) Shall be exposed at all times.

C. When a boiler or pressure vessel stamp is indistinct:

  (1) An inspector shall direct the owner to have the boiler or pressure vessel restamped;

  (2) The owner shall:

    (a) Request from the chief boiler inspector permission to restamp, and

    (b) Submit with the request, proof of the original stamp; and

  (3) If the chief boiler inspector authorizes restamping, an inspector shall:

    (a) Observe the restamping, and

    (b) File with the chief boiler inspector notice of the restamping, and a facsimile of the stamp applied.

D. A condemned boiler or pressure vessel shall be stamped with:

  (1) Letters 5/16 of an inch in height; and

  (2) The configuration XXX MD XXX.