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Safety Valve Selection Guide

The document discusses different types of safety relief valves, including their designs and specifications. It provides information on conventional, balanced, and pilot-operated safety valves. It also defines terms like superimposed back pressure and blowdown. Charts are presented comparing parameters like allowable back pressure and materials for different valve manufacturers and models.

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李天
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207 views118 pages

Safety Valve Selection Guide

The document discusses different types of safety relief valves, including their designs and specifications. It provides information on conventional, balanced, and pilot-operated safety valves. It also defines terms like superimposed back pressure and blowdown. Charts are presented comparing parameters like allowable back pressure and materials for different valve manufacturers and models.

Uploaded by

李天
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
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Conventional

排氣孔要塞住

調整Blow down(關閉壓力)
Balanced Bellow

可以微調設定壓力

排氣孔不能塞住

降低背壓影響
Balanced -Piston

多了一個塞頭 排氣孔不能塞住
Conventional-Threaded

螺紋方式連接
SIMMER POP-OPEN
名詞解釋
Superimposed Back Pressure: 安全閥出口原來已存在的靜壓力，可能是固定或變動值
假設是排放到大氣，其背壓值就是1大氣壓

Acc. to ASME BPVC VIII Section I: Coefficient of discharge = KD = actual flow/theoretical flow

Kb = vapor flow factor = Capacity with Back Pressure/Rated Capacity without Back Pressure
當設定壓力(SP)為10Kg/cm2 g
1.Conventional:背壓<1 Kg/cm2 (因為不可高於SP的10%)

Hint:實務上面來講超過一點點，可以藉由調整spring load來克服

2.Balanced:背壓<5 Kg/cm2 (因為不可高於SP的50%),最好請製造商來確認排放量

3.Pilot-Operated:背壓多少不影響

4.Overpressure: 20%代表超過SP的百分比=比SP高2 kg/cm2

5.Blowdown: 10%代表SP與關閉壓力差1 kg/cm2,也就是關閉壓力為9 kg/cm2

安全閥入口管線壓降<0.3 Kg/cm2 (因為不可高於SP的3%)


ARI
ARI-REYCO R Series- Safety Relief Valve (Full Nozzle)
找ARI型錄中”Fig. … .971
acc. to API526
找ARI型錄中”Fig. … .973

找ARI型錄中”Fig. … .974

gastight cap
open lifting device

closed lifting device


LESER
LESER-Types 441 ANSI-Flanged Safety Relief Valve

Conventional design
Materials(材質)
LESER型錄上的編碼:舉例441.4813
依此類推有Air, Water可以查
依此類推有Air, Water可以查
①

②
①

Coefficient of discharge = Kb = Kdr/αw


FARRIS
Farris 2600 Series的Model Number, Ex: 26EA10-170

Prefix: N/A

26: serial number

E: API letter

A: Conventional construction
1: (1) 入口溫度範圍-20~800℉; (2) Body & Bonnet-Carbon Steel; (3) Spring: Chrome Alloy
Farris 2600 Series的Model Number, Ex: 26EA10-170

0: 150#

X-: N/A

1: Raised Face, ASME Std. (125 to 160 AARH)

7: Open Lever

0: Without Gag

/S4: N/A
Selection Chart (E Orifice)
Cap Construction
Cap Construction
Case: 火災情況選用不同型安全閥計算面積公式比較
GE Consolidated
Consolidated 1900 Series的Valve Type, Ex: 1906-00E-2-CC-TD-34-RF-SS-HP
Sat’d steam
Superheated steam, Ksh

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