Labor & Industries (L&I), Washington State

Anhydrous Ammonia

Chapter 296-826, WAC

WAC 296-826-500

Appurtenances

Appurtenance means all devices such as pumps, compressor, safety relief devices, liquid-level gauging devices, valves and pressure gauges.

Safety relief devices

Don't have discharge termination in or beneath any building.

Safety relief valves

Have a flow capacity that isn't restricted by any connection to it on either the upstream or downstream side.

Connections to containers

Have shut off valves located as close to the container as possible.

Exemption: Safety relief devices, gauging devices or devices fitted with a No. 54 drill size hole aren't required to have shut off valves located as close to the container as possible.

Connections and the line, including valves and fittings

Have a greater rated flow than the excess flow valves that protects them

Excess flow valves, where required

Meet all of the following:

• Are designed with a bypass no larger than a No. 60 drill size opening to allow equalization of pressures.
• Close automatically at the rated flow of vapor or liquid specified by the manufacturer.
• Maintain legible markings.

Excess flow valves provided with shut off valves

Excess flow and back pressure check valves, where required

Are designed to close if the shut off valve breaks during installation

Are located either:

• Inside the container
  or
• Outside the container as long as the excess flow valve is:
  • -As close as possible to the entrance of the line
    and
  • -Installed without excessive stress that could result in breakage between the container and the valve.

Liquid level gauging devices that:

Require bleeding of the product into the atmosphere such as the rotary tube, fixed tube, and slip tube devices

Are either:

• Designed so that the maximum opening of the bleed valve isn't larger than No. 54 drill size
  or
• Provided with an excess flow valve.

Exemption:

• -If openings from the containers or through fittings are attached directly onto the container where pressure gauge connections are made, then there's no need for excess flow valves as long as the openings aren't larger than a No. 54 drill size
• -This requirement doesn't apply to farm vehicles used for the application of ammonia as covered by WAC 296-826-50030.

Exemption:

The rate of discharge of spring-loaded safety relief valves installed on underground containers may be reduced to 30 percent of the rate of discharge specified in Table 6, Safety Relief Valve Rate of Discharge so long as the container isn't uncovered after installation until the liquid ammonia has been removed.

Note:

A relief valve manufacturer's tolerance of plus 10 percent is permitted.

20

258

145

1,310

340

2,640

1,350

8,160

25

310

150

1,350

350

2,700

1,400

8,410

30

360

155

1,390

360

2,760

1,450

8,650

35

408

160

1,420

370

2,830

1,500

8,900

40

455

165

1,460

380

2,890

1,550

9,140

45

501

170

1,500

390

2,950

1,600

9,380

50

547

175

1,530

400

3,010

1,650

9,620

55

310

180

1,570

450

3,320

1,700

9,860

60

360

185

1,600

500

3,620

1,750

10,090

65

408

190

1,640

550

3,910

1,800

10,330

70

455

195

1,670

600

4,200

1,850

10,560

75

762

200

1,710

650

4,480

1,900

10,800

80

804

210

1,780

700

4,760

1,950

11,030

85

845

220

1,850

750

5,040

2,000

11,260

90

885

230

1,920

800

5,300

2,050

11,490

95

925

240

1,980

850

5,590

2,100

11,720

100

965

250

2,050

900

5,850

2,150

11,950

105

1,010

260

2,120

950

6,120

2,200

12,180

110

1,050

270

2,180

1,000

6,380

2,250

12,400

115

1,090

280

2,250

1,050

6,640

2,300

12,630

120

1,120

290

2,320

1,100

6,900

2,350

12,850

125

1,160

300

2,380

1,150

7,160

2,400

13,080

130

1,200

310

2,450

1,200

7,410

2,450

13,300

135

1,240

320

2,510

1,250

7,660

2,500

13,520

140

1,280

330

2,570

1,300

7,910

Cylindrical container with hemispherical heads

Area = overall length in feet times the outside diameter in feet times 3.1416

Cylindrical container with other than hemispherical heads

Area = (overall length in feet plus 0.3 outside diameter in feet) times outside diameter in feet times 3.1416

Spherical container

Area = outside diameter in feet squared times 3.1416

Note:

• Vent pipes from 2 or more safety relief devices located on the same unit, or similar lines from 2 or more different units, may be run into a common header if:
  • -The cross-sectional area of the header is at least equal to the sum of the cross sectional areas of the individual vent pipes.
    

Exemption:

• You are exempt from the requirement not to install the shut off valve between the safety relief valve and the container or systems in the following situations:
  • -A 3-way valve installed under 2 safety relief valves, each with:
    • The required rate of discharge
      and
    • Installed to allow either of the safety relief valves to be closed off but not at the same time.
  • -Two separate relief valves are installed with individual shut off valves.
  • -The 2 shut off valve stems must be mechanically interconnected to allow the full required flow of one safety relief valve at all times.
  • -When a safety relief valve manifold that allows:
    • One valve of 2 or more to be closed off
      and
    • The remaining valve or valves will provide not less than the rate of discharge shown on the manifold nameplate.

Exemption:

• The following don't need to be fitted with excess flow valves:
  • -Safety relief valves
  • -Liquid level gauging devices that require both of the following:
    • Bleeding of the product into the atmosphere
    • Construction so that outward flow won't exceed that passed by a No. 54 drill size opening
  • -Those with openings from the containers or through fittings that are attached directly onto the container where pressure gauge connections are made as long as:
    • The openings aren't larger than a No. 54 drill size.

Columnar-type gauges

• Are restricted to stationary storage installations
• Are shielded against the direct rays of the sun
• Are equipped with all of the following:
• -Shut off valves having metallic hand-wheels
• -Excess flow valves
• -Extra heavy glass that's adequately protected with a metal housing applied by the gauge manufacturer

Main shut off valves

• Are kept closed and locked when the installation is unattended

Exemption: Valve locks aren't required if the facility is protected against tampering by fencing or other suitable means.

Underground installations with a probability of the manhole or housing becoming flooded

• Have vent lines located above the high water level
• Have manholes or housings with ventilated louvers or their equivalent with the area of their openings equal or exceeding:
  • -The combined discharge areas of the safety relief valves and vent lines which discharge their content into the manhole housing

W =

34,500 F A (0.82)

____________________

L

Q (a)=

633,000 F A (0.32)
______________

LC

Exemption:

Shut off valves don't need to be provided on connections with a No. 54 drill size restriction

Note:

• Install, when operating conditions make it advisable, both of the following:
  • -A check valve on the fill connection
  • -A remotely operated shut off valve on other connections located below the maximum liquid level.

Exemption:

• You're exempt from the requirement not to install the shut off valve between the safety relief valve and the container or systems in the following situations:
  • -A 3-way valve installed under 2 safety relief valves, each with:
    • The required rate of discharge
      and
    • Installed to allow either of the safety relief valves to be closed off but not at the same time.
    -Two separate relief valves are installed with individual shut off valves.
  • -The 2 shut off valve stems must be mechanically interconnected to allow the full required flow of one safety relief valve at all times.
  • -When a safety relief valve manifold that allows:
    • One valve of 2 or more to be closed off
      and
    • The remaining valve or valves will provide not less than the rate of discharge shown on the manifold nameplate.
• Follow additional requirements found in Table 11, Appurtenances for Systems Mounted on Trucks, Semi-Trailers and Trailers

All container connections

• Are provided with either of the following:
  • -Automatic excess flow valves
  • or
  • -Quick-closing internal valves that remain closed except during delivery operations

  Note: If the control mechanism is provided with a secondary control remote from the delivery connection, then a fusible section (melting point 208°F to 220°F) is required to permit the internal valve to close automatically in case of fire.

  Exemption: Filling connections, safety relief devices, and liquid level and pressure gauge connections are exempt from automatic excess flow valves and quick-closing internal valves.

Filling connections

• Prevent back-flow in the event the filling connection breaks with at least one of the following:
  • - Automatic back pressure check valves
  • - Excess flow check valves
  • - Quick closing internal valves

  Exemption:

• An automatic valve isn't required if:
• -The filling and discharge connect to a common opening in the container shell
• and
• -The opening is fitted with a quick-closing internal valve

Nonrecessed container fittings and appurtenances

• Are protected against physical damage by one of the following methods:
  • -A protected location
  • -The vehicle frame or bumper
  • -A protective housing that meets the following:
    • Is fabricated from material that's compatible with the containers design and construction requirements
    • Designed to withstand static loadings in any direction equal to twice the weight of the container and attachments when filled using a safety factor of not less than 4, based on the ultimate strength of the material used

    Note: Protect nonrecessed container fittings and appurtenances with a weather cover as needed for proper operation of valves and safety relief devices

Columnar-type gauges

• Are restricted to stationary storage installations
• Are shielded against the direct rays of the sun
• Are equipped with all of the following:
  • -Shut off valves having metallic hand-wheels
  • -Excess flow valves
  • -Extra heavy glass that's adequately protected with a metal housing applied by the gauge manufacturer

Hydrostatic relief valves

Are installed between each pair of valves in the liquid ammonia piping or hose.

Exemption:

• The following don't need to be fitted with excess flow valves:
  • -Safety relief valves
  • -Those with openings from the containers or through fittings that are attached directly onto the container where pressure gauge connections are made as long as the openings aren't larger than a No. 54 drill size.

Exemption:

• You're exempt from the requirement not to install the shut off valve between the safety relief valve and the container or systems in the following situations:
• -A 3-way valve installed under 2 safety relief valves, each with:
• The required rate of discharge
  and
• Installed to allow either of the safety relief valves to be closed off but not at the same time.
• -Two separate relief valves are installed with individual shut off valves.
• The 2 shut off valve stems must be mechanically interconnected to allow the full required flow of one safety relief valve at all times.
• -When a safety relief valve manifold that allows:
  • One valve of 2 or more to be closed off
    and
  • The remaining valve or valves will provide not less than the rate of discharge shown on the manifold nameplate.

Exemption:

• You're exempt from the requirement not to install the shut off valve between the safety relief valve and the container or systems in the following situations:
• -A 3-way valve installed under 2 safety relief valves, each with:
• The required rate of discharge
  and
• Installed to allow either of the safety relief valves to be closed off but not at the same time.
• -Two separate relief valves are installed with individual shut off valves.
• -The 2 shut off valve stems must be mechanically interconnected to allow the full required flow of one safety relief valve at all times.
• -When a safety relief valve manifold that allows:
  • One valve of 2 or more to be closed off
    and
  • The remaining valve or valves will provide not less than the rate of discharge shown on the manifold nameplate.

Filling connections

• Are fitted with one of the following:
• -A combination back-pressure check valve and excess flow valve
• -One double or 2 single back-pressure check valves
• -A positive shut off valve used with either an:
  • Internal back-pressure check valve

  or

  • Internal excess flow valve

Exemption: An excess-flow valve isn't required in either of the following:

• -Vapor connection providing you meet both of the following:

• The controlling orifice isn't in excess of 7/16 of an inch in diameter

and

• The valve is hand-operated (attached hand-wheel or equivalent) shut off valve

or

• -In the liquid withdrawal line if the controlling opening between the contents of the container and the outlet of the shut off valve don't exceed 7/16 inch in diameter.

Note: To assist in filling applicator tanks, you're allowed to bleed vapors into the open air if you meet the above requirements.

Columnar-type gauges

• Are shielded against the direct rays of the sun
• Are equipped with all of the following:
  • -Shut off valves having metallic hand-wheels
  • -Excess flow valves
  • -Extra heavy glass that's adequately protected with a metal housing applied by the gauge manufacturer

• An applicator tank that's both of the following:

-Trailed

and

-The metering device is remotely mounted (for example on a tractor tool bar)

Use an automatic break-away type, self-closing, coupling

Note:

• Metering devices may be connected directly to the tank withdrawal valve.
• A union type connection is acceptable between the tank valve and metering device

Hydrostatic relief valves

Are installed between each pair of valves in the liquid ammonia piping or hose.