Pressure Instruments Sample Clauses

Pressure Instruments. Pressure gauge case sizes shall be 4.5 inches. Connections shall normally be 0.5-inch MNPT for 4.5-inch locally mounted gauges. Receiver gauges and 1.5 to 2.5-inch gauges shall be 0.25 inch NPT. Wherever necessary for Facility operation, either industrial-type, 4.5-inch diameter pressure gauges with white face and black scale markings or indicating pressure transmitters shall be provided. Dials shall be white, non-rusting metal or plastic with black figures. Manufacturer’s standard dial faces shall be provided. Dials or pointers shall be field adjustable for zero alignment. These requirements do not apply to 1.5-inch and 2-inch gauges. Steam pressure sensing transmitters or gauges mounted above the steam line shall be protected by a loop seal or a siphon. Siphons shall be installed on pressure gauges in steam service as required by the system design. Pressure gauges on process piping shall generally be visible 10 feet from an operator's normal stance at floor level and shall be resistant to Facility atmospheres. Pressure gauge accuracy shall be ±0.5% of full range per ANSI Specification B40.1, Grade 2A. Pressure devices on pulsating services shall be equipped with pulsation dampers. Pressure devices subject to shock during equipment starts, stops or transient conditions shall be installed on an isolated gauge panel. In general, pressure instruments shall have linear scales with units in psig. Fire protection system pressure gauges shall be designed in accordance with Underwriters Laboratories (UL) standards. Pressure test points shall be equipped with isolation valve and cap or plug. Pressure gauges shall be provided with either a blow-out disk or a blow-out back. Pressure gauges shall have acrylic or shatterproof glass faces. ACC vacuum shall be measured by an absolute pressure transmitter and shall be indicated in the central control room. Differential pressure instruments shall normally be of the manometer type, either liquid-filled, bellows, or force-balance type according to requirements. Pressure gauge elements in contact with process fluid shall normally be 316 stainless steel, except where the process requires a special material. Elements above 1,000 psig shall be bored instead of drawn with threaded and backwelded connection to the socket and tip. Bronze elements shall normally be used for air service. Sockets and tips shall be stainless steel for stainless steel ▇▇▇▇▇▇▇ tubes, and brass for bronze ▇▇▇▇▇▇▇ tubes, in accordance with manufacturer's ...