Emergency trip valve

Steam Admission Volve(s) Governor Controlled Single, Emergency Trip Valve Combine d with Throttle Valve ... 

An emergency trip of the expander or generator requires fast closing of the trip valve and inlet control valve. An emergency trip also must not adversely affect the differential pressure between the reactor and regenerator. 

Note that the operation of an emergency isolation valve should automatically shut down any pump in the line and trip the fuel supply to any furnace. 

Permanent gamma ray scanning equipment was installed on each separator along with foam density and level recorders in the process control room. An emergency trip system that automatically shuts a valve in the appropriate separator gas line to isolate the separator from the compressor suction drums when a high foam level occurs was added also. A similar trip system was insulted in the gas feed line from the HP separator to the power station... 

First, safety critical systems must be reliable. These systems control releases in the event of accidents. It s necessary to have a critical analyzer, instrument and electrical system test program. This should consist of preventive maintenance and alarm and trip device testing for panel alarms, emergency isolation valves and other critical components. [7]... 

The operators deliberately avoided tripping the reactor, as it had been in the earlier alternator tests, when the emergency stop valve to the turbine was shut to start the test. Automatic insertion of some control rods in fact commenced. 

Emergency shutoff valve. This valve is usually automatic and will shut off the cylinder source when tripped. 

Arrangements have been provided to allow the operation of the channel emergency cooling system to be tested whilst the reactor is running. Similarly, the liquid shutdown trip valves are designed for testing Individually whilst the reactor is in operation. 

Control, emergency trip, and relief valves can be equipped with electrohydrauhc... 

The final control elements utilized are solenoid valves and emergency vent valves. Final control elements are de-energized-to-trip, and go to their safe states on loss of either air or electric utilities (i.e., emergency vent valves fall open). 

Trip speed is the speed at which an independent emergency device is activated and sends a signal to close the expander inlet butterfly valve system. This is approximately 105% of maximum continuous speed or synchronous speed (whichever is higher). 

All valves are equipped with hydraulic actuators, electronic positioning controllers for precise positioning, and solenoid valves for rapid (trip) opening of bypass valves and emergency closure tripping of trip and inlet control valves. 

Ml Ives, burst disks, valves or trips. In addition to hardware systems are human systems such as 1) emergency response, 2) administrative controls,... 

Alarms are used to alert operators of serious, and potentially hazardous, deviations in process conditions. Key instruments are fitted with switches and relays to operate audible and visual alarms on the control panels and annunciator panels. Where delay, or lack of response, by the operator is likely to lead to the rapid development of a hazardous situation, the instrument would be fitted with a trip system to take action automatically to avert the hazard such as shutting down pumps, closing valves, operating emergency systems. 

Each of these steps might be performed either by direct action of operations or emergency response personnel or by automatic systems. An example of the latter might be an array of toxic or flammable gas detectors that might trip an emergency shutdown system that closes remotely actuated block valves and vents off the process pressure to a flare if two adjacent sensors read above a predetermined vapor concentration. 

Aeration was controlled at one of three rates by connecting either a dissolved oxygen (DO) or redox electrode, as appropriate (Section 2.4), to a meter containing a trip amplifier. The trip amplifier operated at two set points and switched two solenoid valves to allow the entry of air at a high or low flow rate through a pipe that emerged under the... 

The primary system is intended to isolate the major equipment in order to prevent reverse flow and exhaust oxides in a gaseous state. It consists of a special restraint type valve (check) and two motorised shutdown valves, arranged in series. The system includes a low pressure detector on the main pipe that trips the sulphuric acid pumps, isolates the process and stops the helium flow into the reactor and heaters (emergency system EAS-200). 

Class 1 safety instrumentation loops include alarms and trips on storage tanks containing flammable or toxic liquids, devices to control high temperature and high pressure on exothermic-reaction vessels, and control mechanisms for low-flow, high-temperature fluids on fired heaters. Other Class 1 instruments include alarms that warn of flame failure on fired heaters, and vapor detectors for emergency valve isolation and sprinkler-system activation. All of these alarms, shutdown valves, and other critical instruments are regularly proof-tested to a well-defined schedule. 

---