welcome to the leser seminar, taipei 28. june 2006ebooks.lib.ntu.edu.tw/1_file/enviro/101206... ·...

1Design_of_safety_relief_valves_250804_Cal

Welcome to the LESER Seminar, Taipei 28. June 2006


Design of safety relief valves


Design of safety valves– Target –

• Classification of Pressure Relief Devices• General design of Safety Relief valves


Design of safety valves– Classification according to ASME PTC

25 –

Reclosing Pressure Relief Device

Pressure relief valve (PRV)

Low lift PRVFull lift PRVPilot operated PRVPower actuated PRV

Safety valve

Relief valve

Safety relief valve (SRV)

Nonreclosing Pressure Relief Device

Rupture disc deviceBuckling pin deviceBursting disc device

Pressure Relief Device (PRD)


Pilot operated safety valve vs. spring loaded safety valve

Spring loaded Pilot operated


Basic design of safety valves– Standard connections –

Threaded connectionFlanged connection

Type 441 Type 526 Type 437 Type 459


Basic design of safety valves– Special connections –

Welded endInlet female connection

• Typical for threaded valves• Large spread of connections


Basic design of safety valves– Nozzle type –

Full nozzle Type 526Semi nozzle Type 441 ANSI

Nozzle

• Mechanically rolled seat to the body• Recognized design in general

industry application

• Threaded nozzle• Recognized design in API

applications

Seat(semi nozzle)


Basic design of safety valves– Blow-down ring –

Type 526 with blow-down ring

Blown-downring

Type 441 without blow-down ring

• Codes and standards which don‘t require a blow-down ring likeASME VIII

• Codes and standards which require a blow-down ring like API 526


Basic design of safety valves– Bellows –

Type 526 without bellowsType 526 with bellows

Bellows

• Protection of inner parts• Back pressure compensation

• Back pressure lower than 15%


Basic design of safety valves– Bonnet –

Closed bonnetOpen bonnet

• Spring cooled by atmosphere • Completely sealed safety valve


Basic design of safety valves– Cap vs. lifting device –

Type 526 lifting device H4Type 526 plain lever H3

• No gastight • Gastight manual lifting possible


Basic design of safety valves– Bolted vs. standard –

Type 526 cap H2Type 526 bolted cap H1

• Only if specification demands • Standard at LESER valves


Basic design of safety valves– Sealing –

Type 526 Soft seal (O-ring)Type 526 metal seat

• Used in standard application • For improved requirements,but limited by temperature andchemical resistance


Basic design of safety valves– Threaded valve type –

Type 459 three-piece assemblyType 437 two-piece assembly

• Inlet body• Outlet body

• Inlet body• Outlet body• Bonnet


Basic design of safety valves– Lift indicator –

Lift indicator closedLift indicator open

• Indication of valve lift to control room

LiftControlroom

Controlroom


Basic design of safety valves– Test gag –

Blocked for revisionSafety valve in use

• The safety valve has to be gagged to perform a pressure test of the plant, otherwise the valve has to be removed or a blind has to be installed before


Basic design of safety valves– Drain hole –

With drain holeWithout drain hole

• Condensed liquid is removed from the body either by free draining design or– if desired – by additional drain hole


Basic design of safety valves– Heating jacket –

With heating jacketWithout heating jacket

• In situations with media with a low Reynolds number (highly viscous fluids) a heating jacket with heated spacer ensures the proper function of a safety valve

• Furthermore it avoids clogging of the safety valve


Product range


Overview

API SeriesType 526

Compact PerformanceType 437

Compact PerformanceType 459

High PerformanceType 441

Clean ServiceType 48X

Critical ServiceType 447


API Series– Series 526 –


Features From To

NPS 1” 8”

Pressure rating #150 #2500

Set pressure range [psig] 15 6000

Orifice D T

Body material WCB, WC6, CF8M



API 526 – Applications

• Large scale chemicalplant– Tank protection– Blow-down systems

• Oil extraction, transportand processing– Drilling platforms– Oilfields (“Christmas

trees“)– Storage tank facilities– Refineries

• NACE applications(e.g., sour gas)

• Pipelines• OEM equipment in

petrochemical plants


Compact Performance– Threaded Safety Relief Valves Series 437, Series 459 –


Features From To

Connection Large variety of connections

Set pressure range DIN [bar]ANSI [psig]

0.215

70010150

Compact Performance– Threaded Safety Relief Valves Series 437, Series 459 –

Pressure rating 16#150

700#2500

DIN [PN]ANSI [PR]

Nominal Pipe Size(NPS), inlet Inlet thread

15½ ’’½ ’’

251’’2’’

DN ANSINPT G


Compact Performance – Applications

• Air/gas compressorsand pumps

• Technical gases and CO2 plants

• Chemical equipmentand piping

• Pressure vessels and piping systemscontaining gas, air, liquid or steam

• LPG/LNG terminals, carriers etc.

• Cryogenic systemsand oxygenapplication

• Thermal Relief


High Performance– Flanged Safety Relief Valves Series 441 DIN, ANSI, XXL –


High Performance– Flanged Safety Relief Valves Series 441 DIN, ANSI, XXL –

Features From To


0.215

40580


40#300

DIN [PN]ANSI [PR]

Nominal Pipe Size(NPS), inlet

20¾ ’’

40016’’

DN ANSI

Connection Flanged connections


• Gas/air separation plants

– Large mass flow

– High accumulation

rates

• Liquids at large massflow

– High pressure pumps

– Chemical reactors

• Power stations

• Liquid gases

• Natural gas services

• Boilers

High Performance – Applications


Clean Service– Safety Relief Valves for clean service applications: Series 48X –


Clean Service– Safety Relief Valves for clean service applications: Series 48X –

Features From To


0.115

162175


16#150

DIN [PN]ANSI [PR]


10½

1004

DN ANSI

Connection Large variety of connections


Clean Service – Applications

•Food industry

•Dairy

•Brewery

•Pharmaceuticalindustry

•Chemical industry

•Multi-purposeplants

•Cosmetic industry


Critical Service– PTFE-lined Safety Relief Valves: Series 447 –


Critical Service– PTFE-lined Safety Relief Valves: Series 447 –

Features From To

Option


0.1515

16232


40#150

DIN [PN]ANSI [PR]


251’’

1004’’

DN ANSI

Type 447: fully linedType 546: PTFE-nozzle


Critical Service – Application

•Chlorine manufacture

•Reducing acids

•Alkalis

•Dump sewage•High back

pressure (= 50%)and corrosion

•MDI-plants(Methydiisocyanat)

•Phosgene plants

•Multiple product systems


Safety valves with upstream KUB bursting disc

B

A

C

E

D

B Reverse buckling pin bursting disc

C Two piece holder (outlet and inlet connection part)

D Space monitoring device

E Pressure Gauge

A Safety valve


Safety valves with upstream KUB burstingdisc

Features From To

• Combination of advantages of bursting disc and safety valve

• Type test approved


2.030

1201740


LESER

01/29/02

The final curtain

The End

welcome to the leser seminar, taipei 28. june 2006ebooks.lib.ntu.edu.tw/1_file/enviro/101206... ·...

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