Texas Administrative Code › Title 16 - ECONOMIC REGULATION › Part 4 - TEXAS DEPARTMENT OF LICENSING AND REGULATION › Chapter 65 - BOILERS › Subchapter R - TECHNICAL REQUIREMENTS › Section 65.609 - Process Steam Generators

Current through Reg. 49, No. 28; July 12, 2024
(a)
				  Some process steam generators referred to in §
										RSA 65.2,
				  are shown in §
										RSA
				  65.615, Exhibits 4 and 5.
(b) The steam collection or liberation drums
				  of a process steam generator shall be constructed in accordance with the
				  American Society of Mechanical Engineers (ASME) Section VIII, Division 1,
				  Division 2, or Division 3. As an alternate, the process steam generator may be
				  constructed to ASME Code, Section I.
(c) When the owner/operator elects to
				  construct a process steam generator to ASME Code, Section I, the limits as
				  shown in §
										RSA
				  65.615, Exhibits 4 and 5, are as defined in
				  the rules of ASME Section I.
(d)
				  Safety valves and pressure relief valves.
(1)
				  The use of weighted-lever safety valves or safety valves having either the seat
				  or disk of cast iron is prohibited.
(2) Each ASME Code, Section VIII, Division 1
				  or Division 2, steam collection or liberation drum of a process steam
				  generator, shall have at least one safety valve designed for steam service in
				  accordance with applicable ASME Code of Construction. The valve body drain
				  shall be open and piped to a safe point of discharge.
(A) The installation of full-area stop valves
				  between the steam collection or liberation drum of a process steam generator
				  and the safety valve is permitted as depicted in §
												RSA
				  65.615, Exhibits 4 and 5. A full-area stop
				  valve may be installed on the discharge of the safety valve when connected to a
				  common header. Stop valves shall be car sealed or locked in the open
				  position.
(B) One or more safety
				  valves on every steam collection or liberation drum of a process steam
				  generator shall be set at or below the MAWP. The remaining valves, if any,
				  shall be set within the range specified and have the capacity required by the
				  applicable ASME code.
(3) Each ASME Code, Section I, process steam
				  generator, shall have one safety valve and if it has more than 500 square feet
				  (47 square meters) of bare tube water heating surface, it shall have two or
				  more safety valves. ASME Code, Section I, safety valves shall be applicably
				  stamped.
(A) The valve or valves shall be
				  connected to the steam collection or liberation drum of the process steam
				  generator, independent of any other steam connection, and attached as close as
				  practicable to the steam collection or liberation drum without unnecessary
				  intervening pipe or fittings.
(B)
				  No valves, except as defined in §65.2(14), of any description shall be
				  placed between the required safety valve or pressure relief valve or valves and
				  the steam collection or liberation drum, nor on the discharge pipe between the
				  safety valve or pressure relief valve and the atmosphere.
(C) The safety valve capacity of each process
				  steam generator, shall allow the safety valve or valves to discharge all the
				  steam that can be generated by the process steam generator without allowing the
				  pressure to rise more than 6.0% above the highest pressure to which any valve
				  is set, and to no more than 6.0% above the MAWP.
(4) When a discharge pipe open to the
				  atmosphere is used, it shall be at least full size of the safety valve
				  discharge and fitted with an open drain to prevent water lodging in the upper
				  part of the safety valve or discharge piping. The drain or drains shall be
				  piped to a safe point of discharge. When an elbow or fitting is installed on
				  the discharge pipe it shall be located close to the safety valve outlet. The
				  discharge pipe shall be securely anchored and supported. All safety valve
				  discharges shall be located or piped to a safe point of discharge clear from
				  walkways or platforms. If a muffler is used on a pressure relief valve, it
				  shall have sufficient area to prevent back pressure from interfering with the
				  proper operation and discharge capacity of the valve.
(5) When two or more steam collection or
				  liberation drums of process steam generators, operating at different pressures
				  and safety valve settings are interconnected, the lower pressure process steam
				  generator(s) or interconnected piping shall be equipped with safety valves of
				  sufficient capacity to prevent overpressure, considering the maximum generating
				  capacity of all of the process steam generators.
(6) Safety valve and pressure relief valve
				  mountings.
(A) For ASME Code, Section I
				  installations, safety valves or pressure relief valves shall be connected so as
				  to stand in the upright position, with spindle vertical. The opening or
				  connection between the boiler and the safety valve or pressure relief valve
				  shall have at least the area of the valve inlet.
(B) For ASME Code, Section VIII, Division 1
				  or Division 2 installations, safety valves or pressure relief valves normally
				  should be installed in the upright position, with spindle vertical. Where space
				  or piping configurations preclude such an installation, the valve may be
				  installed in other than the vertical position, provided that:
(i) the valve design is satisfactory for such
				  position;
(ii) the media is such
				  that material will not accumulate at the inlet of the valve; and
(iii) drainage of the discharge side of the
				  valve body and discharge piping is adequate.