Pneuamtic On-Off ESDV Type 6" – 36” Ball Valves
The function of the shutdown valve is to shut-off the fluid flow
inside the fluid flow line or pipe when an emergency that leads to
a hazardous situation comes. It is an actuator operated valve
mainly used for safety purpose that is why it is called Emergency
shutdown valve. It is also known as the shutdown valve or SDV,
ESDV, ESV, ESD
It is very important that every instrument engineer must know where
the shutdown valve is installed, what fluid flow through it and
what standard is used as the design reference. These shutdown
valves are commonly used in oil and gas field in order to reduce
the escalation of hazards from one system to other.
shutdown valve features :
i) Tie Shut Off
- a shutdown valve must possess Zero/minimum leakage. Generally, it
should pass the seat leakage testing as per API 508 and/or ISO5208.
ii) Fire-safe
- shutdown valve must work even though it is exposed to external fire
attacks. Thus, shutdown valve body shall be fire-rated according to
API 607 for soft seated valve or API 6FA for API 6A & API 6D
valves or BS 6755 Part 2.
iii) Fast action (From Full Open - Full Close)
- The actions of the shutdown valve must be fast. A quarter ball
valve is best for quick action. According to thumb rule, shutdown
valve shall be able to close within 10 seconds of activation, and
time taken from Full open to Full Close must be within 1-2 seconds
per inch of shutdown valve size. Therefore, proper selection and
sizing of the actuator must be ensured and all requirements must be
fulfilled.
iv) Minimum passing (when closed)
- This feature is needed to minimize the potential of the
overpressure of a low-pressure system and spurious trip. A shutdown
valve with equal% characteristic (most ball valve will have this
feature. However, this shall be confirmed with valve supplier) is
the preferred type. With equal% characteristic, it can operate with
10% valve closure give 20% flow reduction, 20% closure give 50%
closure.
v) Minimum disturbance/turbulence to process fluid
- This feature is to minimize unnecessary energy lost. Reduced Bore
(RB) ball valve having a hole in the middle would minimize flow
direction change and turbulence. Full Bore (FB) ball valve
virtually like a pipe- significantly minimize energy lost.
vi) Fail-safe
- A shutdown valve actuator shall pneumatic/hydraulic fail-safe
spring-return type. If a shutdown valve fails to close electrical
driven type shall not be used.
vii) Manual field reset
- A shutdown valve must manually be operated at the site. The
operator shall ensure that the system is clear and safe and also,
can be reset on site. No remote reset is allowed.
Full Open Position – Normal Operation
The ESDV provides minimal pressure Differential when Differential
when the valve the valve is in full-open-open position.
The full bore ball valve virtually acts like a pipe minimizing
process fluid turbulence
Full Closed Position – Emergency Situation
Specifications:
- Material: SS304/316/304L/316L ( CF8/CF8M/CF3/CF3M), WCB, etc.
- Full port
- Size: 1/2"~12" (DN15~DN300)
- W. P.: ANSI STANDARD: CLASS 150LB~1500LB; DOMESTIC STANDARD:
PN10-40; JIS STANDARD: JIS10K etc. (CAN BE CHOSEN)
- W. T.: -20ºC ~200ºC (-4ºF~392ºF)
- Investment casting
- Blow-out proof stem
- Anti-static device &Fire proof devide (option)
- With ISO 5211 Mounting pad
- Design & Manufacture standard: API 6D, API 608, BS 5351.
- Flange dimension: ASME B16.5
- Face to face: ASME B16.10
- Test & Inspect standard: API 598, API 6D.
- Pressure & Temperature standard: ASME B16.34