Ch. 701                                      1994 LAWS OF MARYLAND           

(7)      SUBJECT TO THE PROVISIONS OF SUBSECTION (E) OF THIS SECTION,
VESSELS FOR CONTAINING WATER UNDER PRESSURE, INCLUDING THOSE
CONTAINING AIR, THE COMPRESSION OF WHICH SERVES ONLY AS A CUSHION, WHEN
NONE OF THE FOLLOWING LIMITATIONS ARE EXCEEDED:

(I)       A DESIGN PRESSURE OF 300 PSI; OR                 

(II)     A DESIGN TEMPERATURE OF 210 DEGREES FAHRENHEIT.

(8)      Hot water supply boilers which are directly fired with oil, gas or
electricity when none of the following limitations are exceeded:                 

(i) Heat input of 200,000 BTU/hr.[,];                   

(ii) Water temperature of [200° F.,] 210 DEGREES FAHRENHEIT; OR

(iii) Nominal water capacity of 120 gals. These exempt hot water supply
boilers shall be equipped with safety relief valves.

(9)      MECHANICAL DEVICES OF THE FOLLOWING TYPES

(I)      PUMPS;                                         

(II)     COMPRESSORS;                                                                                  

(III)    TURBINES;

(IV)    GENERATORS; AND

(V)     HYDRAULIC AND PNEUMATIC CYLINDERS.                 

(b)     The following boilers and pressure vessels shall be exempt from the
requirements of §§ 176, 177 and 178 of this subtitle:

(1)      Boilers or pressure vessels located on farms and used solely for
agricultural purposes.

(2)      Heating boilers which are located in private residences or in apartment,
houses of less than six (6) family units.

(3)      Pressure vessels containing only water under pressure for domestic
supply purposes, including those containing air, the compression of which serves only as a
cushion or airlift pumping system, when located in private residences or in apartment
houses of less than six (6) family units.

(4)      Exhibition or antique boilers or pressure vessels, including, but not
limited to, steam or gas engines, wheat threshers and antique tractors, if these boilers or
pressure vessels have been inspected and issued a valid certificate of safety by another
state, and have been brought into this State to be used in temporary exhibits or shows.

(c)      The provisions of this subtitle do not apply to the water containing portions of
an air-conditioning or refrigeration system condenser or evaporator;

(1) That use halocarbon refrigerant;

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