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ASME CSD-1-2009 pdf download

ASME CSD-1-2009 pdf download.Controls and Safety Devices for Automatically Fired Boilers.
(c) Except as allowed in (d) below, the handle for all manually operated shutoff valves shall be permanently attached. (d) Where permanently attached handles are not available or where the handle of a manual shutoff valve creates a personnel obstructionorhazard whenthe valve is in the closed position, a removable handle shall be permitted provided all the following requirements are satisfied: (1) The handle shall remain installed on the valve at all times when the valve is open. (2) Following removal, reattachment shall only be possible such that the handle is perpendicular to the gas flow with the valve in the closed position. (3) Valve position shall be clearly indicated whether the handle is attached or detached. (4) Upon removal, the valve handle shall be reori- ented (turned 180 deg) and reattached to eliminate the personnel obstruction or hazard, or if remaining detached, the valve handle shall be tethered to the gas main no more than 3 ft from the valve in a manner that does not cause personnel safety issues and allows trouble-free reattachment of the handle and operation of the valve without untethering the handle. (5) A handle tethered in accordance with (4) above shall only be permitted when the line in which the valve is located is tagged/locked out to prevent operation. (e) A manually operated shutoff valve, as described in (a) through (d) above, shall be provided upstream from all other main gas line controls to isolate the boiler fuel train from the fuel supply. The valve shall be located within 6 ft of the boiler and must be readily accessible from the boiler room floor.
(f) When the pilot gas supply is obtained indepen- dently from the main burner fuel supply or upstream of the manual shutoff valve required in (e) above, a manually operated shutoff valve, as described in (a) through (d) above, shall be located in the gas supply line to the pilot burner(s). When the pilot gas supply is obtained downstream of the manual shutoff valve required in (e) above, one or more manual shutoff valves or other means shall be provided as required to permit pilot turndown tests and/or pressurization of the pilot fuel train without pressurizing the main fuel train. (g) A manually operated shutoff valve, as described in (a) through (d) above, shall be provided after the downstream safety shutoff valve for each fuel train. CF-160 Gas-Pressure Regulators (a) Individual gas-pressure regulators or gas-pressure regulators that are part of a combination valve shall be furnished for both pilot fuel lines (if a pilot is used) and main fuel lines of gas-fired boiler units in accordance with ANSI Z21.78/CSA 6.20, Combination Controls for Gas Appliances. The gas pressure at the outlet of the regulator shall be within ±10% ofthe regulation setpoint at all firing rates. A pressure test port shall be provided to permit measuring the gas pressure to confirm compli- ance with the requirements of this paragraph. (b) Gas-pressure regulators incorporating integral ventlimiters shall complywith the applicable provisions of ANSI Z21.18/CSA 6.3, Gas Appliance Pressure Regulators. (c) Second stage gas-pressure regulators on boilers firing liquefied-petroleum gas or LP-gas air mixtures shall comply with UL 144, Standard for LP-Gas Regulat- ing, and shall be installed in accordance with the NFPA 58, Liquefied-Petroleum Gas Code. CF-161 Overpressure Protection (a) When the maximum allowable working pressure of any component is less than the gas pressure entering a building, so that failure of a gas system pressure regu- lator would produce downstream pressures greater than that rating, the downstream piping system shall be pro- vided with overpressure protection. (b) Gas overpressure protection devices, if required, shall be located upstream of all operating and safety controls and in both the main burner and, if applicable, the pilotburnergas supplysystem. The gas overpressure protection devices shall be vented to a safe point of discharge, if required. (c) Refer to CG-210 for additional requirements. (d) Overpressure protection, if required, may be pro- vided by any of the devices listed in the latest edition of NFPA 54/ANSI Z223.1, National Fuel Gas Code.

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