5.1.2 Student Book © 2005 Propane Education & Research CouncilPage 1 NFPA 58, LP-Gas Code, sets out the minimum valve and fitting requirements for propane

5.1.2 Student Book © 2005 Propane Education & Research Council Page 1

NFPA 58, LP-Gas Code, sets out the minimum valve and fitting requirements for propane tanks used to supply dispensers. Selecting or verifying that dispenser tank valves and fittings are proper for a certain installation requires an examination of the application and operating requirements for the dispenser, and company operating procedures.

5.1.2Identifying Required Dispenser

Tank Valves and Fittings

In this module you will learn to:

1. Identify NFPA 58 code requirements for ASME tank valves & fittings

2. Verify proper specifications and protection measures for tank relief valves

3. Verify that proper components for the dispenser installation are provided


Identifying NFPA 58 code requirements for ASME tank valves and fittings

NFPA 582004

1.3.2 (11) Propane dispensers located at multiple fuel refueling stations shall comply with NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages.

NFPA 58 definitions of propane dispensers are given in:3.3.21.1 Dispensing Station3.3.21.2 Vehicle Fuel Dispenser


NFPA 58 required dispenser tank valves and fittings

generally include:

1. Double backflow check filler valve (tanks with filler opening less than 1½ inch diameter)

2. Manual shutoff valve for vapor service

3. Fixed maximum liquid level gauge, often a component of a multi-valve including a manual shutoff valve

4. Internal spring-type relief valve (aboveground tanks; external type for underground tanks)

5. Float gauge

6. Actuated liquid withdrawal excess-flow valve (this valve is optional when a liquid withdrawal valve with excess-flow is provided)


Dispenser tank valves and fittings that are optional or not specifically required by Table 5.7.7.1 generally include:

7. Backflow check and excess-flow vapor return valve(s)

8. Manual shutoff liquid valve with internal excess-flow check valve

9. Pressure gauge (tanks greater than 4000 water gallons)

Dispenser supply tanks typically incorporate items 1, 2, 3, 4, 5, and 8.


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Va lv e

F i l l e rV a l v e O p t io n a l A c tu a te d

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* O p tio n a l if 5 . 7 . 7 . 1 (C )N F PA 5 8 , 2 0 0 4 , a p p lie s

In te rn a l Exc e ss F lo w /Em e rg e n c y Sh u td o w n

M a n u a lV a l v e

F ix e d M a x. L iq u id Le v e l G a u g e /V a p o r R e tu rn V a lv e

V a r i a b l e L iq u idLe v e l ( F l o a t )G a u g e

W e a th e r C a p

R e l ie f Va lv e P ip e dto a P o in t 7 F e e tA b o v e C o n ta in e rsO v e r 2 , 0 0 0 W a te r G a l lo n sC a p a c it y

Figure 1. Required and Optional Dispenser Supply Tank Valves & Fittings


001.5

E x te rn a lB y - p a ss

M e te rEm e rg e nc yBre a k-a wa y

M o to r/M o b ileFue l Filling

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M e te rVa p o r Se n sin g

Lin e

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Inte rna l Exc e ss F lo w/Em e rg e nc y Shu td o wn

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Stra ine r

M a xim u m 1 0 Fe e t(Sh o rte r is b e tte r)

Pum pBy-p a ss

Line

Va p o r Re tu rnVa lv e w / E xc e ssF lo w

F le x ib leSe c t io n

M u lti-Va lv e o rVa p o r Re tu rn Va lv ew / E xc e ss F lo w

Figure 2. Dispensing Station/Vehicle Fuel Dispenser Component Diagram


NFPA 582004

5.2.1.8 Containers in dispensing stations not located in LP-Gas bulk plants, industrial plants, or industrial applications shall have an aggregate water capacity not greater than 30,000 gallons.

5.7.7.4 ASME containers over 4000 gallons water capacity shall also be equipped with the following appurtenances:

1) An internal spring-type, flush-type full internal, or external pressure relief valve (see Annex E)

2) A fixed maximum liquid level gauge

3) A float gauge, rotary gauge, slip tube gauge, or a combination of these gauges

4) A pressure gauge

5) A temperature gauge


Verifying proper specifications and protection measures for tank relief valves

Courtesy of Sherwood Division of Harsco

Figure 3. Internal Type Relief Valve

Figure 4. Container Surface Area (97.5 SQ. FT.)On ASME Data Plate


NFPA 582004

6.7.2.4 Rain caps or other means shall be provided to minimize the possibility of the entrance of water or other extraneous matter into the relief device or any discharge piping. Provision shall be made for drainage where the accumulation of water is anticipated.

6.7.2.5 The rain cap or other protector shall be designed to remain in place, except during pressure relief device operation, and shall not restrict pressure relief device flow.

6.7.2.7 The pressure relief valve discharge on each aboveground container of more than 2000 gallon water capacity shall be piped vertically upward to a point at least 7 feet above the top of the container, and the discharge opening shall be unobstructed to the open air.


Verifying that proper components for the dispenser installation are provided

Filler valve or other filling systems

Figure 5. Double Backflow Check Filler Valve for Tanks with Filling Opening Less Than 1½ Inch



Dispenser supply tanks over 4,000 gallons water capacity or having a filling opening diameter 1½-inch or larger require a transfer bulkhead equipped with an emergency shutdown valve (ESV) for the vapor equalizing connection (if 1¼-inch or larger), and an ESV for the liquid fill connection. A backflow check valve may be used for the liquid line if flow of liquid is limited to one direction (into the dispenser supply tank).

Figure 6. Transfer Bulkhead and Emergency Shutdown Valves for Supply Tank with Filling Opening 1½ Inch (Liquid) or Larger


Internal valves and excess flow requirements

The dispenser supply tank liquid opening that connects to the propane transfer pump must be fitted with an internal excess-flow valve. For supply tanks not located in a bulk or industrial plant having water capacities of 4,000 gallons or less a positive shutoff valve must be provided in conjunction with the internal excess-flow in one of the two methods listed below:

1. A manual valve located in the piping immediately down-stream of the excess-flow

2. An internal valve which incorporates the excess-flow and a positive shutoff


E X C E S S F L O WVA LV E

1 /4 T U R NM A N U A L VA LV E

L IQ U ID F L O W

VA LV E D IS C

Figure 7. Excess Flow Valve and Manual Valve for Liquid Withdrawal


Figure 8. Internal Valve for Liquid Withdrawal (Shown in a Vertical Tank)


Emergency shutdown systems

Figure 9a. Cable Actuated Liquid Withdrawal Valve

Figure 9b. Pneumatic Actuated Liquid Withdrawal Valve


Manual valves

Figure 10. Multi-valve Courtesy of Sherwood Division of Harsco

Courtesy of Engineered Controls International Inc(REGO)

Figure 11. Manual Valve with Excess-Flow

Courtesy of Jomar International

Figure 12. Ball Valve


Tank Fittings


13. Float Gauge

a. b.

14a. Fixed Maximum Liquid Level Gauge with Dip Tube

14b. Multi-valve with Fixed Maximum Liquid Level Gauge


Optional Gauges (Required for tanks larger than 4000 Gallons)

Figure 15. 0-300 PSI Pressure Gauge

Figure 16a. Tank Thermometer Well

Figure 16b. Dial Indicating Thermometer

5.1.? Student Book © 2005 Propane Education & Research Council Pages 13-15

Time to See If You Got the Key Points of This Module…

• Complete the Review on pages 13-14.

• See if you are ready for the Certification Exam by checking off the performance criteria on page 15.

Documents

5.1.2 Student Book © 2005 Propane Education & Research CouncilPage 1 NFPA 58, LP-Gas Code, sets out the minimum valve and fitting requirements for propane