Iranian Classification Society Rules

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Section 3 Process System Equipment


301. General

This Section provides requirements for process equipment that are typically utilized in the unit.


302. Pressure vessels


1. Pressure vessels are to be designed, constructed, and tested in accordance with the ASME Boiler and Pressure Vessel Code Section VIII Division 1 or Division 2 or other recognized standards.


2. Low melting point or brittle materials such as cast iron, aluminum, brass, copper, or fiberglass, are not to be utilized in pressure retaining parts of vessels containing flammable or toxic fluids.


3. Supports and insulation of vessels subject to change in temperature are to be designed to accom- modate the resulting thermal movement.


303. Heat exchangers


1. Process heat exchangers with a design pressure in excess of 0.1 MPa and handling flammable fluids are subject to the requirements of 302. and the following applicable requirements:


2. Tubular heat exchangers are to comply with applicable sections of ASME Boiler and Pressure Vessel Code Section VIII, Division 1 or Division 2, TEMA Standards or API Std. 660.


3. Plate and frame exchangers may be employed for handling flammable liquid, with the following re- strictions:

(1) Safety or protective devices are to be provided as required in accordance with of API RP 14C, Appendix A, A10.

(2) Each exchanger is to be provided with an exchanger enclosure, protective wall, shield or similar barrier, capable of containing spray in case of gasket leakage during operation.

(3) Each exchanger is to be provided with spill containment and drain capable of handling a liquid

release of at least 10% of the maximum flammable stream flowrates.

4. Air-cooled heat exchangers are to comply with API Std. 661.

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304. Fired vessels


1. All fire-tube type fired vessels, with a shell operating pressure greater than 0.1 MPa, are to be de- signed in accordance with Section I of ASME Boiler and Pressure Vessel Code. Fired vessel shells, coils or other equipment designed in accordance with ASME Boiler and Pressure Vessel Code are

to conform to all applicable requirements of 302.


2. Indirect fired water bath heaters with working pressures lower than 0.1 MPa are to be designed and fabricated in accordance with API Spec. 12K.


3. Direct fired vertical or horizontal emulsion treaters are to be designed and constructed in accord- ance with API Spec. 12L.


4. Where burner ignition or light-off is part of an automatic sequence, the following control functions are to be provided:

(1) Automatic timed purge interval prior to admitting pilot fuel. Purge may be by fan if equipped, or by time delay to allow natural draft purge.

(2) Firing limit on a trial for ignition (15 seconds maximum) on each attempted pilot light-off.

(3) Confirmation of pilot lighting prior to admitting main burner fuel.

5. Each burner designed for manual light-off of the pilot is to be designed to allow an operator to light the pilot from a location which limits his exposure to flame flashback, should it occur. Burners are to be equipped with a sight-glass suitable for verifying pilot light-off and for viewing of main flame.


6. Combustion air intakes for fired vessels are to be located in a safe area.


7. Any fired vessel installed within a firewall is to be arranged with means of shutdown from outside the firewall enclosure.


305. Compressors


1. Gas compressors are to comply with applicable API standards according to their types. Compressors rated for less than 0.7 MPa and 28.3 mĖĤmin can be accepted on the basis of manufacturer’s decla- ration of conformity and test reports.


2. A fusible plug fire detection system, directly activating the emergency shutdown system, is to be installed in the compressor package. The emergency shutdown system is to be interlocked to shut- down the compressor.


306. Pumps


1. Centrifugal pumps intended for hydrocarbon service are to comply with API Std 610. Centrifugal pumps having stuffing box pressures in excess of 1.4 MPa are to be provided with either mechan- ical seals with alarm or mechanical seals with means to collect and contain seal leakage.


2. Pumps rated for 0.7 MPa and 757 ThĤmin or less may be accepted for hydrocarbon service, on the basis of a manufacturer’s declaration of conformity with the requirement of API Std. 610.


3. Pumps rated above 0.7 MPa and 757 ThĤmin are to meet the following requirements:

(1) The manufacturer is to supply a manufacturer’s declaration of conformity to API Std. 610 to the Society and is to include documentation on the seal arrangement of the pump.

(2) The manufacturer is to submit a statement indicating any system or components not in com-

pliance with the requirements, detailing and clarifying all deviations to API Std. 610, paragraph

6.1.5 to the Society.

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