Freeze Protection Guidance.pdf

Typical Methods for Applying Self-Regulating Heat Tape

Design Criteria (Apply to All Tables):

1. Maintain fluid above 40° Fahrenheit.

2. Maintain minimum ambient temperature above 40° Fahrenheit.

3. Insulate using tubular foam plastic (Rubber-Tex or equivalent).

4. Quick disconnects are to be freeze protected by using removable heat trace across the joints, and by insulating the joint with a removable insulated joint cover.

5. Energize heat tape from heat tape control panels.

Table 1: Typical Maximum Circuit Length

HEAT TAPE RATING

(WATTS/FT)

CIRCUIT BREAKER SIZE VS MAXIMUM CIRCUIT

LENGTH (FEET)

10A 15A 20A 8 125 150 200

NOTES:

1. Service voltage - 120 VAC, Ground Fault Circuit Interrupter (GFCI) protected.

2. Table values are for system startup temperature of 40° F.

3. Heat tapes do not have a minimum circuit length.

4. All installations must be per the National Electric Code.

5. For any clarification of the National Electric Code, contact cognizant technical code.

Table 2: Metal Pipe

PIPE SIZE

(OD)

INSULATION

THICKNESS (IN)

HEAT TAPE

RATING (WATTS/FT)

STRAIGHT SPIRALED

1/4 1/2 - 1 8 N/A 1/2 1/2 - 1 8 N/A 3/4 1/2 - 1 8 N/A 1 1/2 - 1 8 N/A

1-1/4 1/2 - 1 8 N/A 1-1/2 1/2 - 1 8 N/A

2 1/2 - 1 8 8 2-1/2 1/2 - 1 8 8

NOTE: Spiral factor is 1.32 feet of heat tape per 1 foot of pipe.

Table 3: Metal Tubing

INSULATION

THICKNESS (IN)

HEAT TAPE

RATING (WATTS/FT)

STRAIGHT SPIRALED

3/8 1/2 8 N/A 1/2 1/2 - 1 8 N/A 3/4 1/2 - 1 8 N/A 1 1/2 - 1 8 N/A

1-1/4 1/2 - 1 8 N/A

Table 4: Non-Metallic Pipe and Tubing

INSULATION

THICKNESS (IN)

HEAT TAPE

RATING (WATTS/FT)

STRAIGHT SPIRALED

1/4 1/2 - 1 8 N/A 3/8 1/2 - 1 8 N/A 1/2 1/2 - 1 8 N/A 3/4 1/2 - 1 8 N/A 1 1/2 - 1 8 8

1-1/4 1/2 - 1 8 8 1-1/2 1/2 - 1 8 8

2 1/2 - 1 8 8 2-1/2 1/2 -1 8 8

4 1 8 8

NOTE: Spiral factor is 1.32 feet of heat tape per 1 foot of pipe. Secure heat tape to hose every 2 to 3 feet.

Positioning and Attachment of Heating Elements (Typical)

Figure 1

Allowable Methods for Applying End Caps

Manufacturer's Kit (Long Sleeve Version)

Figure 2

Heat Shrink End Caps

Figure 3

NOTE: Methods differing from these shown may be used, if approved by cognizant technical code.

Typical Splice and Tee Connection Kits

Figure 4

Heat Tracing Pressure Regulators and Other Complex Components with Several Tubes

Figure 5

Heat Tracing Cutoff Valves for Bleeder Protected Systems

Figure 6

1. Exact configuration may vary.

2. For removable components, leave a loop of tracing long enough to make breaking the circuit unnecessary.

3. Take care to keep the flat side of the heater in as good physical contact with the body as possible.

4. Fully insulate and weather protect.

Heat Tracing 8" Diameter Fresh Water Manifolds

Figure 7

Table 5

HEATER CABLE RATING

(WATTS/FT)

REQUIRED LENGTH

(FT INCHES)

8 6' 3"

1. Length required to protect manifold is shown in table.

2. Take care to keep the flat side of the heater in as good physical contact with the manifold body as possible.

3. Fully insulate and weather protect.

GENERAL NOTES:

1. Heat tapes do not have a minimum length restriction.

2. Heat tapes may be overlapped. Wrap valves and flanges as shown.

3. Run heat tape along pipe or tubing.

4. Test each circuit after thermal insulation installation. Testing with a 500-volt D.C.

megger is acceptable. Minimum insulation resistance reading should be 20 megohms, regardless of length. If insulation resistance falls below the minimum reading:

a. Determine the cause of the insulation resistance drop, and take corrective action.

b. If damaged, remove the entire damaged section of heat tape and splice in a new section of heat tape, using approved splice kits.

5. Use stock numbers listed in table 6 for specific heat tape, or use one that meets the requirements of this PI.

Table 6

HEATER CABLE

RATING

(WATTS/FT)

STOCK NUMBER FOR

INDUSTRIAL GRADE

HEAT TAPE

RAYCHEM INDUSTRIAL

GRADE HEAT TAPE

PART NUMBER

8 LLDM10259EL 8BTV1-CR

Table 7

WOODHEAD CONNECTORS

MALE 24W47

FEMALE 25W47

END CAP 50W50