EMERSON Guide PED - Direct Spring Operated Safety Valves, Sapag-EN

PED - Installation and Operational Safety Instructions Direct Spring Operated Safety Valves

Before installation these instructions must be fully read

SAPAG

and understood

General Storage and handling The intent of these instructions is to acquaint Because cleanliness is essential to the satisfactory operation and tightness of a safety valve, the user with the storage, installation and precautions should be taken during storage to keep out all foreign materials. Inlet and outlet operation of this product. protectors should remain in place until the valve is ready to be installed in the system. Take care This Safety Valve should only be used in to keep the valve inlet absolutely clean. It is recommended that the valve be stored indoors in the accordance with the applicable operating original shipping container away from dirt and other forms of contamination. instructions and within the application Safety valves must be handled carefully and never subjected to shocks. Rough handling may alter specifications of the purchase order. the pressure setting, deform valve parts and adversely affect seat tightness and valve performance. These valves have been tested and adjusted at The valve should never be lifted or handled using the lifting lever. the factory. Contact the Factory or a Emerson When it is necessary to use a hoist, the chain or sling should be placed around the valve body and

authorized representative before making any bonnet in a manner that will insure that the valve is in a vertical position to facilitate installation.

changes to the settings.

Installation Many valves are damaged when first placed in service because of failure to clean the connection properly when installed. Before installation, flange faces or threaded connections on both the valve inlet and the vessel and/or line on which the valve is mounted must be thoroughly cleaned of all dirt and foreign material. Because foreign materials that pass into and through safety valves can damage the valve, the systems on which the valves are tested and finally installed must also be inspected and cleaned. New systems in particular are prone to contain foreign objects that inadvertently get trapped during construction and will destroy the seating surface when the valve opens. The system should be thoroughly cleaned before the safety valve is installed. The gaskets used must be dimensionally correct for the specific flanges. The inside diameters must fully clear the safety valve inlet and outlet openings so that the gasket does not restrict flow. For flanged valves, draw down all connection studs or bolts evenly to avoid possible distortion of the valve body. For threaded valves, do not apply a wrench to the valve body. Use the hex flats provided on the inlet bushing. Safety valves are intended to open and close within a narrow pressure range. Valve installations require accurate design both as to inlet and discharge piping. Refer to International, National and Industry Standards for guidelines.

Inlet piping Connect this valve as direct and close as possible to the vessel being protected. The valve should be mounted vertically in an upright position either directly on a nozzle from the pressure vessel or on a short connection fitting that provides a direct, unobstructed flow between the vessel and the valve. Installing a safety valve in other than this recommended position will adversely affect its operation. The valve should never be installed on a fitting having a smaller inside diameter than the inlet connection of the valve.

Discharge piping Discharge piping should be simple and direct. A “broken” connection near the valve outlet is preferred wherever possible. All discharge piping should be run as direct as is practicable to the point of final release for disposal. The valve must discharge to a safe disposal area. Discharge piping must be drained properly to prevent the accumulation of liquids on the downstream side of the safety valve. The weight of the discharge piping should be carried by a separate support and be properly braced to withstand reactive thrust forces when the valve relieves. The valve should also be supported to withstand any swaying or system vibrations. If the valve is discharging into a pressurized system be sure the valve is a “balanced” design. Pressure on the discharge of an “unbalanced” design will adversely affect the valve performance and set pressure. Fittings or pipe having a smaller inside diameter than the valve outlet connections must not be used. The bonnets of balanced bellows safety valves must always be vented to ensure proper functioning of the valve and to provide a telltale in the event of a bellows failure. Do not plug these open vents. When the fluid is flammable, toxic or corrosive, the bonnet vent should be piped to a safe location.

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