4.2.5 student book © 2004 propane education & research councilpage 1 4.2.5 preparing...

4.2.5 Student Book © 2004 Propane Education & Research Council

4.2.5Preparing Foundations for Cylinders & ASME Tanks

An important step in preparing for and installing a propane distribution system is assuring that each container (whether a DOT cylinder or ASME tank) has an appropriate foundation.

In this module you will learn to prepare:

(1) A foundation for a DOT cylinder installation

(2) A foundation for an ASME tank installation

(3) A foundation for a temporary installation

4.2.5 Student Book © 2004 Propane Education & Research Council Page 1

Preparing a Foundation for a Cylinder Installation

Three types of cylinder foundations include:

• Solid Masonry Blocks

• Pre-Cast Concrete Circles, Squares, or Rectangles

• Concrete Poured in Place

Solid Masonry Blocks— If drainage is a problem, it is a good practice to use masonry blocks and raise the cylinder(s) above the ground sufficiently to avoid water damage to the foot ring.

Figure 1.

Figure 2.



Pre-Cast Concrete Circles, Squares, or Rectangles

Figure 3. Circular Pre-Cast FoundationsSupporting Cylinders

Concrete Poured in Place— In some areas (usually in flood zones), state and local codes require that all propane containers be installed and secured to a concrete (poured in place) foundation. Check your company standard operating procedures & state and local codes for requirements on concrete foundations.



Steps in Preparing the Location

Step 1: Locate the marker or stake for the location of the cylinder.

Step 2: Mark off an area that is at least 1-inch larger in all directions than the foundation blocks or platform to be used.

Step 3: Dig a shallow hole about 2-inches deep (or ½ the depth of the masonry block) that is the size of the foundation

Figure 5. Pre-CastConcrete Foundation




Step 4: Fill the hole with 1 to 2 inches of coarse sand.

Step 5: Tamp the sand down.

Step 6: Refill the hole as necessary until the sand bed is level.

Figure 6. Preparing Foundation Using Pre-Cast Concrete Foundation




Step 7: Place the platform on top of the sand and make sure the platform is seated.

Step 8: Using a carpenter’s bubble level, check the level of the block foundation from end to end, side to side, and diagonally.

Figure 7. Checking the Block Foundation with Carpenter’s Level




Step 9: Once the foundations have been prepared, store all tools and equipment in the truck.

Note:If a poured in place concrete foundation is used, the excavation will be deeper to accommodate the coarse sand and 3 to 4 inches of concrete fill.


Preparing a Foundation for an ASME Tank Installation

Aboveground ASME Tank Installation

Horizontal ASME tanks designed for permanent installation in stationary service aboveground shall be placed on masonry or other noncombustible structural support and located on concrete or masonry foundation with tank supported as follows (NFPA 58, 2001 edition):

• Where saddles are used, allow for expansion and contraction.

Figure 8. ASME Storage Container with Concrete Saddles

4.2.5 Student Book © 2004 Propane Education & Research Council Pages 5 & 6



• Containers of more than 2,000 gallons water capacity shall be provided with concrete or masonry foundations formed to fit the tank contour or, if furnished with saddles, in compliance with NFPA 58, Table 2.2.5.1, shall be placed on flat-topped foundations.

Figure 9. Typical Smaller ASME Container Aboveground Installation




Figure 9. Typical Smaller ASME Container Aboveground Installation




Step 1: Locate the marker or stake for the location of the tank.

Step 2: Cut all grass, weeds, hay, etc. ten (10) feet in all directions from the location of the tank. Remove any dry or cut debris from the area.

Step 3: Mark off two areas for the masonry blocks.

Step 4: Dig two (2) holes that are at least one-half the depth of the mounting blocks.

Step 5: Pour a 2” layer of coarse sand in each hole.

Step 6: Install the masonry blocks.




Step 7: Level the foundation and the tank.

Step 8: Once the masonry blocks have been set and leveled, pick up and store all tools and materials.

Note:

On multi-tank installations, ensure that all foundations are level and, if the tanks have inter-connecting piping at the bottom, the maximum fill level for the tanks is at the same height.



Underground ASME Tank Installation

When the backfill is placed, it should be free of rocks and similar abrasives that can adversely affect the coating.

Figure 10. Typical Small ASME Container Underground Installation




Figure 11. Typical Large ASME Container Underground installation




Step 1: Locate the marker or stake for the location of the tank.

Step 2: Cut all grass, weeds, hay, etc. ten (10) feet in all directions from the location of the tank. Remove any dry or cut debris from the area.

Step 3: Use the tape measure to determine the following:

• Overall length of the tank

• Overall width of the tank

• Distance between the bottom of the mounting feet and the top of the shroud or manhole

Step 4: Mark off an area that is 12” wider and 12” longer than the overall width and length of the tank.




Step 5: Check state and local codes for requirements on the depth of the hole for the tank.

Step 6: Dig the hole for the tank.

• Be sure the walls are as vertical as possible, except that in loose or sandy loam soil it may be necessary to slope the walls to protect against possible cave-ins.

• If the hole is deeper than 4’, it may be necessary to brace the sides of the hole with plywood.

Step 7: For the foundation, pour at least 6” of coarse sand in the bottom of the hole and tamp down.

Step 8: Using the carpenter’s level, ensure that the sand bottom is relatively level.


Preparing a Foundation for a Temporary Installation

Temporary, single, portable container installations have applications such as fuel supplies, crop drying, road construction, building construction, etc.

Such temporary installations shall be placed on firm earth, concrete pads, or paved surfaces, and are limited to 12 months by NFPA 58. The authority having jurisdiction be notified before starting temporary installations using containers of over 2,000 gallons individual water capacity.

The surface for such temporary service must be level and if not paved, shall be clear of grass, weeds, and other combustible materials within 10 feet of the container. Flexibility must be provided for the connecting piping.

Where portable containers are installed for temporary service, the outside bottom of the container must not exceed 5 feet aboveground.

4.2.5 Student Book © 2004 Propane Education & Research Council Pages 12 - 15

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

• Complete the Review on pages 12 & 13.

• See if you are ready for the Certification Exam by checking off the performance criteria on pages 14 & 15.

4.2.5 student book © 2004 propane education & research councilpage 1 4.2.5 preparing...

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