1.1 This specification covers the minimum requirements for the manufacture of pressure vessels with diameter not exceeding 4 feet and a tangent-to-tangent length not exceeding 12 feet, under the following design conditions: a) Design pressure no greater than 1.69 MPa (245 psi) and, b) Design temperature no greater than 121°C (250°F) Note: Such vessels are also referred to as small pressure vessels. 1.2 Vessels under the scope of this specification are purchased on a stand-alone basis or as an integral part of a skid-mounted packaged equipment unit. Note: This is applicable irrespective of the party contractually responsible for the purchase order. 1.3 The requirements are in addition to and supplement the requirements of the ASME Boiler and Pressure Vessel Code Section VIII D1. 1.4 This specification does not cover in-service pressure vessels and pressure vessels stamped “UM” per ASME SEC VIII D1. 1.5 Pressure vessels having partial or complete cladding shall also conform to the proponent standard if exist in addition to the requirements of this specification. 1.6 This specification does not cover pressure vessels under the following services and design conditions: a) Hydrogen service. b) Lethal service. c) Cyclic service. d) Vessels which required design wall thickness is not governed by loadings due to wind pressure or earthquake forces. e) Devices used as an integral part of piping systems, made of what are recognized as piping components (piping, fittings, etc.) and serve purposes such as straining, filtering, mixing, separating, distributing, metering and controlling flow. f) Pressure vessels used as part of heating, ventilation and air conditioning (HVAC) systems. g) Compressed gas cylinders. 1.7 Where a licensor's specification requirement is more stringent than that of this specification, the licensor's specification requirement will govern. 1.8 A vessel that is an integral part of a skid-mounted packaged equipment unit shall be designed and manufactured by a manufacturer of such unit per the relevant database.