【国外标准】 Standard Specification for Spray Shields for Mechanical Joints

This specification describes the manufacturing requirements for spray shield stock and the fabrication and installation requirements for spray shields made from that stock. The physical and mechanical properties for the aluminized glass cloth, thread, and protective outer jacket shall be as specified. If lacing hooks or rings are of the type that fastens by stitching, the hooks or rings shall be attached to the backup washers using a wire stitch machine and wire. The methods for testing the aluminized glass cloth, thread, and protective outer jacket shall be as specified.1.1 This specification describes the manufacturing requirements for spray shield stock and the fabrication and installation requirements for spray shields made from that stock.1.1.1 Sections 2 – 14 address the manufacturing requirements for the spray shield stock. Annex A1 addresses the fabrication and installation requirements for the spray shields.1.1.2 Fig. 1 shows the typical construction of a spray shield. Figs. 2-6 show methods of installation of a spray shield on various mechanical joints.FIG. 1 Spray Shield Construction (Typical)FIG. 2 Installation of Butterfly Valve ShieldFIG. 3 Spray Shield for Pump Inlet HeadFIG. 4 Spray Shield for Simplex StrainerFIG. 5 Spray Shield for Butterfly ValveFIG. 6 Spray Shield for Valve Bonnet1.2 The shields are intended for use around mechanical joints (flanged, bolted unions, and so forth) in liquid piping systems with an internal pressure exceeding 26.1 psi (0.18 N/mm2) to prevent the impingement of flammable liquid on hot surfaces or fluids onto electrical switchboards and components resulting from a leak in the mechanical joint, unless otherwise invoked by contractual requirements. Spray Shields are excluded on all suction lines with a head pressure less than 26.1 psi (0.18 N/mm2) and mechanical joints in non-flammable liquid systems in excess of 10 ft of an electrical switchboard, unless otherwise invoked by contractual requirements.21.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.