API-RP-576

More documents

Recommendations

Info

Valve Opening. In an upset situation a safety valve will open at a predetermined set pressure. The spring force Fs is acting in closing direction and Fp, the force created by the pressure at the inlet of the safety valve, is acting in opening direction. At set pressure the forces F s and F p are balanced. There is no resulting force to keep the disc down on the seat. The safety valve will visibly or audibly start to leak (initial audible discharge). Fion Zhang/ Charlie Chong
The pressure below the valve must increase above the set pressure before the safety valve reaches a noticeable lift. As a result of the restriction of flow between the disc and the adjusting ring, pressure builds up in the so called huddling chamber. The pressure now acts on an enlarged disc area. This increases the force Fp so that the additional spring force required to further compress the spring is overcome. The valve will open rapidly with a "pop", in most cases to its full lift. Overpressure is the pressure increase above the set pressure necessary for the safety valve to achieve full lift and capacity. The overpressure is usually expressed as a percentage of the set pressure. Codes and standards provide limits for the maximum overpressure. A typical value is 10%, ranging between 3% and 21% depending on the code and application. Fion Zhang/ Charlie Chong
Page 1 and 2: API-RP-576 Inspection of Pressure-r
Page 3 and 4: Fion Zhang/ Charlie Chong Speaker:
Page 5 and 6: 5 Causes of Improper Performance 5.
Page 7 and 8: 1 Scope Fion Zhang/ Charlie Chong
Page 9 and 10: The recommendations in this publica
Page 11 and 12: This publication does not cover tra
Page 13 and 14: pressure-relief valves Fion Zhang/
Page 15 and 16: pilot-operated pressure-relief valv
Page 17 and 18: upture disks Fion Zhang/ Charlie Ch
Page 19 and 20: 2 Normative References Fion Zhang/
Page 21 and 22: • ASME PTC 25, Pressure Relief De
Page 23 and 24: 3.1 General For the purposes of thi
Page 25 and 26: galling Fion Zhang/ Charlie Chong
Page 27 and 28: 3.2 Dimensional Characteristics of
Page 29 and 30: inlet size outlet size Fion Zhang/
Page 31 and 32: Fion Zhang/ Charlie Chong huddling
Page 33 and 34: Fion Zhang/ Charlie Chong lift
Page 35 and 36: Basic Function of a Spring Loaded S
Page 37: Valve Closed. In a direct spring lo
Page 41 and 42: Fion Zhang/ Charlie Chong F p = p*A
Page 43 and 44: Functional Diagram. The following d
Page 45 and 46: 3.3 Operational Characteristics—S
Page 47 and 48: 3.3.3 maximum allowable working pre
Page 49 and 50: 3.3.4 maximum operating pressure Th
Page 51 and 52: Fion Zhang/ Charlie Chong Keywords:
Page 53 and 54: 3.4.5 burst-pressure tolerance The
Page 55 and 56: 3.4.10 marked burst pressure or rat
Page 57 and 58: 4 Pressure-relieving Devices Fion Z
Page 59 and 60: 4.2 Pressure-relief Valve Fion Zhna
Page 61 and 62: 4.3 Safety Valve. Fion Zhnag/ Charl
Page 63 and 64: 4.3.1 General. A safety valve is a
Page 65 and 66: 4.3.2 Applications A safety valve i
Page 67 and 68: Fion Zhnag/ Charlie Chong
Page 69 and 70: 4.4.1 General. A relief valve is a
Page 71 and 72: 4.5 Safety-relief Valve. Fion Zhnag
Page 73 and 74: 4.6 Conventional Safety-relief Valv
Page 75 and 76: 4.6 Conventional Safety-relief Valv
Page 77 and 78: http://www.leser.com/en/products/do
Page 79 and 80: Fion Zhnag/ Charlie Chong
Page 81 and 82: Conventional safety valves Fig. 9.2
Page 83 and 84: Types Mediums Limitations Safety-re
Page 85 and 86: 4.7.3 Limitations Balanced safety-r
Page 87 and 88: Fion Zhnag/ Charlie Chong Fig. 9.2.
Page 89 and 90:
Fion Zhnag/ Charlie Chong http://ww
Page 91 and 92:
Fion Zhnag/ Charlie Chong
Page 93 and 94:
4.8 Pilot-operated Pressure-relief
Page 95 and 96:
What is a Pilot operated safety val
Page 97 and 98:
4.8 Pilot-operated Pressure-relief
Page 99 and 100:
Figure 9—High-pressure Pilot-oper
Page 101 and 102:
Page 103 and 104:
4.8.2 Applications Pilot-operated s
Page 105 and 106:
4.9 Pressure- and/or Vacuum-vent Va
Page 107 and 108:
4.9.1 General. • A pressure- and/
Page 109 and 110:
Figure 7—Low-pressure Diaphragm-t
Page 111 and 112:
Figure 10—Weight-loaded Pallet Ve
Page 113 and 114:
Figure 11—Spring and Weight-loade
Page 115 and 116:
Page 117 and 118:
5 Causes of Improper Performance Fi
Page 119 and 120:
Fion Zhang/ Charlie Chong Figure 22
Page 121 and 122:
Figure 25—Monel Rupture Disks Cor
Page 123 and 124:
Fion Zhang/ Charlie Chong
Page 125 and 126:
Page 127 and 128:
Fion Zhang/ Charlie Chong Figure 35
Page 129 and 130:
5.1 Corrosion Fion Zhang/ Charlie C
Page 131 and 132:
Corrosion is a basic cause of many
Page 133 and 134:
http://www.valveworld.net/safetyequ
Page 135 and 136:
Because there is metal-to-metal con
Page 137 and 138:
Basic interferometry The interferen
Page 139 and 140:
As light travels through the Optica
Page 141 and 142:
Example: 1 a series of fringes indi
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Causes of damaged valve seats; 1. C
Page 149 and 150:
Spring failures. 2 modes of failure
Page 151 and 152:
Page 153 and 154:
Fion Zhang/ Charlie Chong The size
Page 155 and 156:
Incorrect calibration of pressure g
Page 157 and 158:
How to adjust a PSV The spring dete
Page 159 and 160:
http://www.cicpro.com/products/safe
Page 161 and 162:
The design of the shroud must be su
Page 163 and 164:
Adjustment pin affect the character
Page 165 and 166:
Page 167 and 168:
5.5 Plugging and Sticking Fion Zhan
Page 169 and 170:
5.6 Misapplication of Materials Fio
Page 171 and 172:
Typical ball valve material selecti
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
5.7 Improper Location, History, or
Page 179 and 180:
Fion Zhang/ Charlie Chong V-203
Page 181 and 182:
Page 183 and 184:
Rough handling can occur during;
Page 185 and 186:
The following table summarises the
Page 187 and 188:
Greater differentials between opera
Page 189 and 190:
5.10 Improper Discharge Piping Test
Page 191 and 192:
Fion Zhang/ Charlie Chong When hydr
Page 193 and 194:
Fion Zhang/ Charlie Chong the bello
Page 195 and 196:
5.11 Improper Handling, Installatio
Page 197 and 198:
Rupture disk problems are often ass
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
6.1 Reasons for Inspection and Test
Page 211 and 212:
6.2.2 Safety 1. proper authority an
Page 213 and 214:
National Board approved ASME stamps
Page 215 and 216:
The Kdr or aW value can vary accord
Page 217 and 218:
6.2.5 Removal of Device from System
Page 219 and 220:
Exercise; Dismantling of PSV Fion Z
Page 221 and 222:
Highly Reactive Materials Water-Rea
Page 223 and 224:
6.2.7 Inspection of Adjacent Inlet
Page 225 and 226:
Fion Zhang/ Charlie Chong Rupture d
Page 227 and 228:
6.2.10 Visual Inspection This inspe
Page 229 and 230:
6.2.11 Dismantling of Valve. Disman
Page 231 and 232:
Page 233 and 234:
Page 235 and 236:
Page 237 and 238:
Portable Test Separator Internal &
Page 239 and 240:
The pilot assembly and dome area co
Page 241 and 242:
6.2.13 Reconditioning and Replaceme
Page 243 and 244:
Fion Zhang/ Charlie Chong Most test
Page 245 and 246:
Page 247 and 248:
After the valve has been adjusted,
Page 249 and 250:
Check for leakage during pressuriza
Page 251 and 252:
Page 253 and 254:
Page 255 and 256:
Page 257 and 258:
6.2.17 Completion of Necessary Reco
Page 259 and 260:
when a valve operates in nonfouling
Page 261 and 262:
ASME BPVC Section I requires; • B
Page 263 and 264:
Page 265 and 266:
Page 267 and 268:
6.2.20 Inspection, Testing, Mainten
Page 269 and 270:
6.2.21 Inspection, Testing, Mainten
Page 271 and 272:
6.3 Visual On-stream Inspection Vis
Page 273 and 274:
6.4.2 Frequency of Shop Inspection/
Page 275 and 276:
Manufacturer’s Basis • Manufact
Page 277 and 278:
API572, 6.4.3 Frequency of Visual O
Page 279 and 280:
Routine • inspection least interf
Page 281 and 282:
7.1 Objective The primary objective
Page 283 and 284:
7.3 Responsibilities Some companies
Page 285 and 286:
Annex A (informative) Pressure-reli
Page 287 and 288:
API576 Charlie Chong/ Fion Zhang/ H
Page 289 and 290:
Page 291 and 292:
A.1 Need and Function of Test Block
Page 293 and 294:
A.2 Testing with Air • Air is com
Page 295 and 296:
A.4 Description of Test Block The s
Page 297 and 298:
Key 1. test station 2. adaptor for
Page 299 and 300:
show all

API-RP-576

Create successful ePaper yourself

Delete template?

Save as template?