1. A. Internal Inspection.

   1. (1) Unless an internal inspection is required by law or by an inspector at the inspector's discretion, a:

      1. (a) Hot water boiler requires only an external inspection for certificate purposes; and
      2. (b) Pressure vessel requires only an external inspection for certificate purposes.
   2. (2) At least 7 days before an internal inspection, the inspector shall notify the owner of the inspection date.

2. B. The owner of a boiler shall prepare the boiler for internal inspection and hydrostatic test, if necessary, by:

   1. (1) Drawing off water and washing the boiler thoroughly;
   2. (2) Removing manhole and handhole plates, washout plugs, and inspection plugs in water column connections;
   3. (3) Cooling and thoroughly cleaning furnace and combustion chambers;
   4. (4) Removing all grates of internally fired boilers;
   5. (5) Removing the pressure gage for testing;
   6. (6) Disconnecting the pipe or valve at the most convenient point to prevent leakage of steam or hot water into the boiler;

   7. (7) Performing the following procedures before opening a manhole or handhole cover and entering any part of a steam-generating unit connected to a common header with other boilers:

      1. (a) Close, tag, and preferably padlock:

         1. (i) Non return and steam stop valves; and
         2. (ii) Feed and check valves;

      2. (b) Open drain valves or cocks between:

         1. (i) Non return and steam stop valves; and
         2. (ii) Feed and check valves; and

      3. (c) After draining the boiler:

         1. (i) Close and padlock the blowoff valves;
         2. (ii) Where practicable, disconnect blowoff lines at a point between pressure parts and valves; and
         3. (iii) Open all drains and vent lines.
3. C. The owner of a pressure vessel shall prepare the pressure vessel for inspection to the extent required by the inspector, using the applicable procedures set out in §B of this regulation.

4. D. Removal of Covering During Inspection.

   1. (1) At each annual inspection, brickwork shall be removed, as required by the inspector, to determine the condition of the boiler, headers, furnace, supports, or other parts.

   2. (2) Unless the information can be obtained by other means, if boiler or pressure vessel jacketing conceals the longitudinal seams of a shell, drum, or dome, sufficient jacketing, setting wall, or other casing or housing shall be removed to permit:

      1. (a) Reasonable inspection of the seams; and

      2. (b) Determination of:

         1. (i) The size and pitch of the rivets; and
         2. (ii) Other data necessary to ascertain the safety of the boiler or pressure vessel.

   3. (3) When an external inspection discloses evidence of a leak or crack:

      1. (a) Sufficient covering shall be removed from the boiler or pressure vessel to permit the inspector to make a safety determination; and

      2. (b) If the covering cannot be removed during the inspection, the inspector may order use of the boiler or pressure vessel discontinued until:

         1. (i) The covering can be removed; and
         2. (ii) Proper inspection can be made.

5. E. Hydrostatic Pressure Test.

   1. (1) A hydrostatic pressure test of a boiler or pressure vessel may not exceed:

      1. (a) 1-1/2 times the maximum allowable working pressure; or
      2. (b) The required test pressure by more than 2 percent.

   2. (2) During a hydrostatic test:

      1. (a) Each safety valve shall be removed; or
      2. (b) Each valve disk shall be held to its seat by a testing clamp, and not by tightening the compression screw on the spring.

   3. (3) Water used to apply a hydrostatic test shall have a:

      1. (a) Recommended minimum temperature of 70°F; and
      2. (b) Maximum temperature of 140°F.

   4. (4) When a hydrostatic test is applied to an existing installation to determine:

      1. (a) Tightness, test pressure shall equal the release pressure of the safety valve having the lowest release setting; and
      2. (b) Safety, test pressure shall equal 1-1/2 times the maximum allowable working pressure.

6. F. If a boiler or pressure vessel is not properly prepared for internal inspection, or if the owner fails to comply with the requirements for a hydrostatic test as set out in this regulation:

   1. (1) The inspector may refuse to conduct the inspection or test; and
   2. (2) If the inspector refuses, the chief boiler inspector shall withhold the inspection certificate until the owner complies with the requirements.

7. G. An inspector is authorized to:

   1. (1) Conduct inspections in accordance with Public Safety Article, §12-909, Annotated Code of Maryland; and
   2. (2) Review and verify records required by Public Safety Article, Title 12, Subtitle 9, Annotated Code of Maryland, and by Codes referenced in Regulation .01-1 of this chapter.

Authority: Public Safety Article, Title 12, Annotated Code of Maryland
Ch. 351, Acts of 2004

Effective date: October 15, 1975 (2:23 Md. R. 1414)

Regulation .02CC amended and .02DD repealed effective June 1, 1982 (9:8 Md. R. 821)

Regulation .02PP amended effective November 4, 1985 (12:22 Md. R. 2103)

Regulations .07—.08 adopted effective November 4, 1985 (12:22 Md. R. 2103)

Regulations .01—.08 repealed and new Regulations .01—.32 adopted effective June 1, 1989 (16:10 Md. R. 1106)

Regulation .01B amended effective September 1, 1989 (16:16 Md. R. 1749); April 16, 1990 (17:7 Md. R. 848); October 7, 1996 (23:20 Md. R. 1422); June 30, 1997 (24:13 Md. R. 930)

Regulation .01B amended as an emergency provision effective July 14, 1999 (26:16 Md. R. 1237); amended permanently effective October 4, 1999 (26:20 Md. R. 1545)

Regulation .01B amended effective July 10, 2000 (27:13 Md. R. 1211)

Regulation .01-1 amended effective January 31, 1994 (21:2 Md. R. 98); July 18, 1994 (12:14 Md. R. 1228); November 20, 1994 (21:25 Md. R. 1933); July 3, 1995 (22:13 Md. R. 966); January 15, 1996 (23:1 Md. R. 23); April 22, 1996 (23:8 Md. R. 604); August 12, 1996 (23:16 Md. R. 1175); June 30, 1997 (24:13 Md. R. 930); November 3, 1997 (24:22 Md. R. 1551); July 10, 2000 (27:13 Md. R. 1211); February 19, 2001 (28:3 Md. R. 205)

Regulation .01-1A(1) amended as an emergency provision effective July 14, 1999 (26:16 Md. R. 1236); amended permanently effective October 4, 1999 (26:20 Md. R. 1545)

Regulation .01-2 adopted effective October 11, 1993 (20:20 Md. R. 1569)

Regulation .01-2 amended effective June 30, 1997 (24:13 Md. R. 930)

Regulation .02A amended effective October 7, 1996 (23:20 Md. R. 1422); July 10, 2000 (27:13 Md. R. 1211); February 19, 2001 (28:3 Md. R. 205)

Regulation .03B amended effective July 3, 1995 (22:13 Md. R. 966)

Regulation .09 amended effective March 5, 1990 (17:4 Md. R. 496)

Regulation .14G adopted effective October 11, 1993 (20:20 Md. R. 1569)

Regulation .15 amended effective September 3, 1990 (17:17 Md. R. 2078)

Regulation .17A amended effective October 11, 1993 (20:20 Md. R. 1569)

Regulation .17A amended as an emergency provision effective July 14. 1999 (26:16 Md. R. 1237); amended permanently effective October 4, 1999 (26:20 Md. R. 1545)

Regulation .17E amended effective September 1, 1989 (16:16 Md. R. 1749)

Regulation .22B amended effective July 3, 1995 (22:13 Md. R. 966)

Regulation .25B amended as an emergency provision effective July 14, 1999 (26:16 Md. R. 1237); amended permanently effective October 4, 1999 (26:20 Md. R. 1545)

Regulation .26B amended effective July 3, 1995 (22:13 Md. R. 966)

Regulation .27 amended as an emergency provision effective July 14, 1999 (26:16 Md. R. 1237); amended permanently effective October 4, 1999 (26:20 Md. R. 1545)

Regulation .27B amended effective August 5, 1991 (18:15 Md. R. 1725); November 20, 1994 (21:23 Md. R. 1933)

Regulation .27C adopted effective August 5, 1991 (18:15 Md. R. 1725)

Regulation .27C amended effective October 11, 1993 (20:20 Md. R. 1569)

Regulation .28A amended effective June 30, 1997 (24:13 Md. R. 930)

Regulation .31D amended effective November 20, 1994 (21:23 Md. R. 1933)

Regulation .32 amended and recodified to Regulation .01-1 effective October 11, 1993 (20:20 Md. R. 1569)

Regulation .32A amended effective April 16, 1990 (17:7 Md. R. 848)

Regulation .33 adopted effective September 1, 1989 (16:16 Md. R. 1749)

Regulation .33A amended, B repealed effective June 30, 1997 (24:13 Md. R. 930)

Regulation .34 adopted effective June 30, 1997 (24:13 Md. R. 930)

Chapter revised as an emergency provision effective August 10, 2001 (28:17 Md. R. 1551); revised permanently effective November 12, 2001 (28:22 Md. R. 1936)

Regulation .01B amended effective December 12, 2002 (29:24 Md. R. 1919); April 23, 2018 (45:8 Md. R. 419)

Regulation .01-1 amended effective April 19, 2021 (48:8 Md. R. 308)

Regulation .01-1A amended effective September 29, 2003 (30:19 Md. R. 1331); March 17, 2014 (41:5 Md. R. 342)

Regulation .01-1A, B amended effective September 2, 2002 (29:17 Md. R. 1380)

Regulation .01-1A, C amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .01-1B, C amended effective December 12, 2002 (29:24 Md. R. 1919)

Regulation .01-2 amended effective December 12, 2002 (29:24 Md. R. 1919); April 23, 2018 (45:8 Md. R. 419)

Regulation .03B, C amended and D adopted effective September 30, 2002 (29:19 Md. R. 1523)

Regulation .08 amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .09 amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .14 recodified to Regulation .14-1 and new Regulation .14 adopted as an emergency provision effective July 9, 2004 (31:18 Md. R. 1348); adopted permanently effective September 27, 2004 (31:19 Md. R. 1431)

Regulation .14C amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .14D adopted effective April 23, 2018 (45:8 Md. R. 419)

Regulation .14-1G amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .15B amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .16 amended as an emergency provision effective December 22, 2008 (36:2 Md. R. 96); emergency status extended at 36:17 Md. R. 1310; emergency status expired November 19, 2009

Regulation .16 amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .16-1 adopted as an emergency provision effective December 22, 2008 (36:2 Md. R. 96); emergency status extended at 36:17 Md. R. 1310; emergency status expired November 19, 2009

Regulation .16-1 adopted effective December 26, 2011 (38:26 Md. R. 1696)

Regulation .16-1 amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .17 amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .17C amended effective December 12, 2002 (29:24 Md. R. 1919)

Regulation .19 repealed and new Regulation .19 adopted effective April 23, 2018 (45:8 Md. R. 419)

Regulation .27A amended effective September 29, 2003 (30:19 Md. R. 1331); April 23, 2018 (45:8 Md. R. 419)

Regulation .27C adopted effective April 23, 2018 (45:8 Md. R. 419)

Regulation .28 amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .28G amended effective July 16, 2020 (47:14 Md. R. 675)

Regulation .28-1 amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .28-2B, F amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .28-3 amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .29 amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .34 amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .35 amended effective April 23, 2018 (45:8 Md. R. 419)

Regulation .37 adopted effective December 12, 2002 (29:24 Md. R. 1919)

Regulation .38 adopted effective December 12, 2002 (29:24 Md. R. 1919)