Anhydrous Ammonia

Chapter 296-826, WAC

Effective Date: 09/01/06

Contents
Index
Download

WAC 296-826-500

Appurtenances

For printing

YOUR RESPONSIBILITY:

To follow the requirements in this section when using appurtenances

Appurtenance requirements for all systems

Nonrefrigerated stationary containers

Refrigerated tanks

Systems mounted on trucks, semi-trailers and trailers
Systems mounted on farm trucks or trailers for transportation of ammonia

Systems mounted on farm equipment for ammonia application

Portable DOT containers

WAC 296-826-50005

Appurtenance requirements for all systems

Definition

Definition:

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

 

You must

  • Make sure each appurtenance installed before February 8, 1973, is determined to be safe by meeting one of the following:
    • -Approved, tested, and installed by either:
    • The American National Standard for the Storage and Handling of Anhydrous Ammonia (in effect at the time of installation)
    • The Fertilizer Institute Standards for the Storage and Handling of Agricultural Anhydrous Ammonia (in effect at the time of installation)
    • -Accepted, certified, listed, or labeled, by a nationally recognized testing laboratory
    • -Inspected or tested by a federal, state, municipal, or local authority responsible for enforcing occupational safety provisions, when no nationally recognized laboratory will provide approval
    • -Tested and approved by a registered professional engineer or other qualified person if the system is a custom-designed or custom-built unit and no other recognized entity will provide approval
    • -Keep a document on file signed by the qualified person that indicates the unit is safe. Include the test bases, test data and results and the qualifications of the qualified person.

You must

  • Make sure container appurtenances are both of the following:
    • -Designed for at least the working pressure for the portion of the system where installed
      and
    • -Fabricated from materials suitable for anhydrous ammonia service.
  • Make sure fixed liquid level gauges, except on refrigerated storage:
    • -Are designed so the maximum volume of the container filled by liquid doesn't exceed 85 percent of its water capacity
      and
    • -Have a coupling into which it's threaded that's placed at the 85 percent level of the container
      • If located elsewhere, install the dip tube of this gauge so it can't be easily removed.
  • Equip each container, except those filled by weight, with an approved liquid level gauging device that does all of the following:
    • -Has a design pressure equal to or greater than the design pressure of the container
    • -Are arranged so the maximum liquid fill level of containers can be readily determined.
  • Follow additional requirements found in Table 5, Appurtenance Requirements for all Systems

Table 5
Appurtenance Requirements for all Systems

If you have

Then make sure they

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.

You must

  • Follow Table 6, Safety Valve Start to Discharge Rate, and Table 7, Safety Relief Valve Rate of Discharge, for the following systems:
    • -Nonrefrigerated stationary containers
    • -Mounted on trucks, semi-trailers, and trailers used for the transportation of ammonia
    • -Mounted on farm wagons for the transportation of ammonia
    • -Mounted on farm equipment for the application of ammonia
Exemption

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.

Table 6
Safety Valve Start to Discharge Rate

Containers

Minimum

Maximum.*

ASME U-68, U-69

110%

125%

ASME U-200, U-201

95%

100%

ASME 1952, 1956, 1959, 1962, 1965, 1968, or 1971

95%

100%

API-ASME

95%

100%

U.S. Coast Guard

(As required by U.S.C.G. regulations)

DOT

(As required by DOT regulations)

Note

Note:

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

Table 7
Safety Relief Valve Rate of Discharge
Instructions are found below the table

Surface Area sq. ft.

Flow Rate CFM Air

Surface Area sq. ft.

Flow Rate CFM Air

Surface Area sq. ft.

Flow Rate CFM Air

Surface Area sq. ft.

Flow Rate CFM Air

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

 

 

 

 

 

  • Table instructions:
    • -The surface area = the total outside surface area of the container in square feet.
    • -When the surface area isn't stamped on the name plate or the marking isn't legible, calculate the area by using the Table 8, Surface Area

Table 8
Surface Area

If you have

Then calculate as follows

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

  • Flow rate--CFM air = cubic feet per minute of air required at standard conditions, 60°F and atmospheric pressure (14.7 psia).
  • The rate of discharge may be altered for intermediate values of surface area.
  • For containers with total outside surface area greater than 2,500 sq. ft., the required flow rate can be calculated using the formula, flow rate CFM air .= 22.11 A0.82 where A .=outside surface area of the container in square feet.

WAC 296-826-50010

Nonrefrigerated stationary containers

IMPORTANT:

In addition to this section, you need to follow the Appurtenances requirements for all systems, WAC 296-826-50005.

You must

  • Make sure all containers are equipped with all of the following:
    • -An approved vapor return valve
    • -A fixed maximum liquid level gauge
    • -A pressure gauge that is both:
      • Graduated from zero to 400 psig
        and
      • Designed for use in ammonia service
  • Provide one or more spring-loaded safety relief valves, or an equivalent type, on all containers.
  • Make sure safety relief valves do all of the following:
    • -Discharge in the following ways:
      • Away from the container in an upward, unobstructed manner into the atmosphere
      • Not in or beneath a building
    • -Have raincaps that allow free discharge of the vapor and prevent the entrance of water
    • -Have a method for draining accumulated condensation
    • -Have a start to discharge, related to the design pressure of the container, according to Table 6, Safety Valve Start to Discharge Rate
    • -Are arranged to minimize the possibility of tampering
    • -Are provided, when the pressure setting adjustment is external, with a means of sealing the adjustment
    • -Have direct communication with the vapor space of the container

Note

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.

You must

  • Protect container appurtenances against physical damage and during transit of containers intended for underground installation.
  • Make sure shut off valves aren't installed between the safety relief valve and the container or system. A shut off valve may be used if arranged so that the required capacity flow is maintained.
Exemption

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.

 

You must

  • Make sure vapor and liquid connections have either of the following:
    • -An approved excess flow valve
      or
    • -An approved quick-closing internal valve that remains closed except during operation.
Exemption

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.

You must

  • Follow additional requirements found in Table 9, Appurtenances for Nonrefrigerated Stationary Containers

Table 9
Appurtenances for Nonrefrigerated Stationary Containers

If you have

Then make sure they

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.

Filling connections

  • Are provided with one of the following:
    • -Combination back-pressure check valve and excess flow valve
    • -One double or 2 single back-pressure check valves
    • -A positive shut off valve in conjunction with either an internal back-pressure check valve or an internal excess flow valve

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

Hydrostatic relief valves

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

WAC 296-826-50015

Refrigerated tanks

IMPORTANT:

In addition to this section, you need to follow the Appurtenances requirements for all systems, WAC 296-826-50005.

You must

  • Protect container appurtenances against the following:
    • -Physical damage during transit of containers intended for underground installation
    • -Damage from vehicles.
  • Make sure safety relief devices have a total relieving capacity larger than either of the following:
    • -A possible refrigeration system upset such as a cooling water failure, power failure, instrument air or instrument failure, mechanical failure of any equipment, excessive pumping rates or changing atmospheric pressure
    • or
    • -The amount based on using either one of the following fire exposure formulas (see note below for codes):
  • Valve manufacturers who use weight of vapors to be relieved as the classifying basis, use this formula:

 

W =

34,500 F A (0.82)

____________________

L

 

 

 

or

  • Valve manufacturers that classify valves based on air flows, use this formula:

 

Q (a)=

 

633,000 F A (0.32)
______________

LC

 

 

 

  • Make sure safety relief devices meet the following additional requirements:
    • -Are set to start-to-discharge at a pressure not in excess of the design pressure of the tank
    • -Have a total relieving capacity sufficient to prevent a maximum pressure in a tank of more than 120 percent of the design pressure.
  • Provide shut off valves for all connections including plugs, safety valves, and thermometer wells:
    • -Locate them as close to the tank as is practical.
Exemption

Exemption:

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

Note

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.


You must

  • Follow requirements found in Table 10, Refrigerated Tank Appurtenances

Table 10
Refrigerated Tank Appurtenances

If you have

Then make sure they

Shut off valves used as a means of lock out for inspection or repair

  • Are of adequate flow capacity
  • Are arranged to be locked or sealed open and not closed except by an authorized person who does both of the following:
  • -Remains there while the valve is closed
  • -Locks or seals the valve open when leaving the station.

Discharge line and header

  • Are designed to accommodate the maximum flow.
  • Have a back pressure not greater than 10 percent of the design pressure of the storage container
  • Include the back pressure in the 120 percent of the maximum pressure of the design pressure.
  • Don't have other containers or systems that exhaust into the discharge line or header.
  • Have vent lines installed to prevent the accumulation of liquid in the lines.

    Note:

    Multiple safety relief valves on the same storage unit may be run through a common discharge header.

Vacuum breakers

Are provided with atmospheric storage

Stacks

  • Do both of the following:
  • -Prevent any obstructions by rain, snow, ice, or condensation
  • and
  • -Have an outlet size not smaller than the size of the safety relief valve outlet connection

You must

  • Make sure appurtenances meet all of the requirements found in the following:
    • -ANSI CGA C-7 2004
    • -ANSI CGA G2.1 1999
    • -API Standard 620 4th Edition, 2002
    • -ASHRAE 15 2004
    • -ASME 2001, Section VIII, Division 1
    • -ANSI B95.1 1977

WAC 296-826-50020

Systems mounted on trucks, semi-trailers and trailers

IMPORTANT:

In addition to this section, you need to follow the Appurtenances requirements for all systems, WAC 296-826-50005.

You must

  • Make sure each container has all of the following:
    • -Fixed maximum liquid level gauging devices
    • -Pressure-indicator gauges with a dial graduated from zero to 400 psig
    • -Either of the following:
      • Equipped for spray-loading, which fills in vapor space
        or
      • Has an approved vapor return valve of adequate capacity.
  • Provide one or more spring-loaded safety relief valves, or an equivalent type, on all containers, that do all of the following:
    • -Discharges in the following ways:
      • Away from the container in an upward, unobstructed manner into the atmosphere
      • Not in or beneath a building.
    • -Has raincaps that allow free discharge of the vapor and prevent the entrance of water
    • -Has a method for draining accumulated condensation
    • -Has a start to discharge, related to the design pressure of the container, according to Table 6, Safety Valve Start to Discharge Rate
    • -Are arranged to minimize the possibility of tampering
    • -Provided, when the pressure setting adjustment is external, with a means of sealing the adjustment
    • -Has direct communication with the vapor space of the container
  • Make sure shut off valves aren't installed between the safety relief valve and the container or system. A shut off valve may be used if arranged so that the required capacity flow is maintained.
Exemption

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

 

Table 11
Appurtenances for Systems Mounted on Trucks, Semi-Trailers and Trailers

If you have

Then make sure they

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.

WAC 296-826-50025

Systems mounted on farm trucks or trailers for transportation of ammonia

IMPORTANT:

  • This section applies to containers of 3,000 gallons capacity or less and pertinent equipment mounted on farm trucks or trailers used for the transportation of ammonia.
  • In addition to this section, you need to follow the Appurtenances requirements for all systems, WAC 296-826-50005.

You must

  • Make sure all containers are equipped with a fixed maximum liquid level gauge.
  • Make sure vapor and liquid connections have either of the following:
    • -An approved excess flow valve
      or
    • -An approved quick-closing internal valve that remains closed except during operation.
Exemption

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.

 

  • Provide one or more spring-loaded safety relief valves, or an equivalent type, on all containers, that do all of the following:
    • -Discharges in the following ways:
      • Away from the container in an upward, unobstructed manner into the atmosphere
    • -Has raincaps that allow free discharge of the vapor and prevent the entrance of water
    • -Has a method for draining accumulated condensation
    • -Has a start to discharge, related to the design pressure of the container, according to Table 6, Safety Valve Start to Discharge Rate
    • -Are arranged to minimize the possibility of tampering
    • -Provided, when the pressure setting adjustment is external, with a means of sealing the adjustment
    • -Has direct communication with the vapor space of the container
  • Make sure shut off valves aren't installed between the safety relief valve and the container or system. A shut off valve may be used if arranged so that the required capacity flow is maintained.
Exemption

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.

You must

  • Secure both ends of the hose while in transit
  • Make sure all containers with a capacity exceeding 250 gallons are equipped with both of the following:
    • -A pressure gauge with a dial graduated from 0-400 psig
      and
    • -A method for spray loading or with an approved vapor return valve
  • Follow additional requirements found in Table 12, Appurtenances for Systems Mounted on Farm Trucks or Trailers

Table 12
Appurtenances for Systems Mounted on Farm Trucks or Trailers

If you have

Then make sure they

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

A fully enclosed guard

  • Have properly vented safety relief valves.

Fittings

  • Are protected from physical damage by a rigid guard designed:
  • -To withstand static loading in any direction equal to twice the weight of the container and lading
  • -With a safety factor of 4 based on the maximum strength of the material used

Liquid withdrawal lines installed in the bottom of the container

Have connections, including the hose, that aren't lower than the lowest horizontal edge of the truck axle

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

Hydrostatic relief valves

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

 

WAC 296-826-50030

Systems mounted on farm equipment for ammonia application

IMPORTANT:

  • This section applies to systems mounted on farm equipment and used for the filed application of ammonia.
  • In addition to this section, you need to follow the Appurtenances requirements for all systems, WAC 296-826-50005.

You must

  • Make sure each container has a fixed maximum liquid-level gauge.
  • Provide one or more spring-loaded safety relief valves, or an equivalent type, on all containers, that do all of the following:
    • -Discharges in the following ways:
      • Away from the container in an upward, unobstructed manner into the atmosphere
      • Not in or beneath a building.
    • -Has raincaps that allow free discharge of the vapor and prevent the entrance of water
    • -Has a method for draining accumulated condensation
    • -Has a start to discharge, related to the design pressure of the container, according to Table 6, Safety Valve Start to Discharge Rate
    • -Are arranged to minimize the possibility of tampering
    • -Provided, when the pressure setting adjustment is external, with a means of sealing the adjustment
    • -Has direct communication with the vapor space of the container

You must

  • Make sure shut off valves aren't installed between the safety relief valve and the container or system. A shut off valve may be used if arranged so that the required capacity flow is maintained.
Exemption

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 13, Appurtenances for Systems Mounted on Farm Equipment for Ammonia Application

Table 13
Appurtenances for Systems Mounted on Farm Equipment for Ammonia Application

If you have

Then make sure they

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.

 

WAC 296-826-50035

Portable DOT containers

IMPORTANT:

  • This section applies to systems that use cylinders, portable tanks (DOT-51), or ton containers (DOT-106A, DOT-110A).
  • In addition to this section, you need to follow the Appurtenances requirements for all systems, WAC 296-826-50005.

You must

  • Make sure safety relief devices meet DOT specifications.
  • Provide the following protection:
    • -To valves and pressure regulating equipment from tampering once installed for use
    • -To containers:
      • From heat sources such as radiant flame and steam pipes. Don't apply heat directly to containers to raise the pressure
      • From moving vehicles or external damage while being stored
      • From ignitable debris and to prevent external corrosion while being stored. Storage can be indoors or outdoors.
  • Protect container valves while in transit, in storage, and while being moved into final use by doing either of the following:
    • -Setting them into the recess of the container
      or
    • -By fastening a ventilated cap or collar to the container that can withstand a blow from any direction equivalent to a 30-pound weight being dropped 4 feet
  • Construction should be such that a blow won't be transmitted to the valves or other connections.
  • Keep outlet valves tightly closed when containers aren't connected for service on all empty or loaded containers
  • Secure the valve protection cap, if the container is designed for one, when the container isn't in service.

 

 

 

End of main content, page footer follows.

Access Washington official state portal

© Washington State Dept. of Labor & Industries. Use of this site is subject to the laws of the state of Washington.