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GT INSTALLATION AND OPERATION INSTRUCTIONS

GAS SUPPLY PIPING

The GT hot water boiler comes from the factory ready to be piped to the gas supply. The National Fuel Gas Code, ANSI Z223.1/NFPA 54 and local codes for gas piping requirements and sizing must be followed. If for any reason the boiler is not for the type of gas available at the installation site, call the nearest Smith distributor to resolve the problem.

Figure 27 depicts the proper way to connect the boiler to the gas supply piping.The manual shut-off valve MUST be installed in the supply piping. It should be approximately 5 ft, 1.5 m, above the floor. Provide a sediment trap/drip leg at the bottom of the vertical section of the gas supply pipe. A ground joint union should be installed between the boiler gas controls and the supply piping. Each of these items is needed to ensure long life and ease of servicing. Always use a pipe sealant that is suitable for use with LP gas. Flexible gas piping is recommended if accepted by the local codes. Make sure the gas piping doesn’t hinder boiler access.

CAUTION: Always use a wrench on the gas valve body when making gas connections to it. Never over- tighten the piping entering the gas valve body or the gas valve will be damaged voiding the warranty!

CAUTION: The gas piping must be properly supported by the building structure and not by the boiler or the gas valve will be damaged voiding the warranty!

Figure 27 - Gas Supply Piping

Table 4 should be used to ensure that the gas supply piping is sized properly. If more than one appliance is supplied by the same supply pipe, the piping must be sized based on the maximum possible demand. Do not neglect the pressure drop due to pipe fi ttings. Table 5 should be used in conjunction with Table 4 to ensure that the gas supply piping is sized properly.

Safe lighting and other performance criteria were met with the gas manifold and control assembly provided on the boiler when the boiler underwent tests specifi ed in ANSI Z21.13/CSA 4.9. All gas connections MUST be leak tested before putting the boiler into operation.

WARNING: Never use an open flame to test for gas leaks. Always use an approved leak detection method. Failure to comply with this WARNING could result in an explosion!

Table 4 - Gas Pipe Capacity

Nominal

 

 

 

Pipe Length

 

 

 

Iron Pipe

10'

20'

30'

40'

50'

60'

80'

100'

150'

Size

 

 

Gas Pipe Capacity (ft3/hr)

 

 

3/4"

278

190

152

130

115

105

90

79

64

 

 

 

 

 

 

 

 

 

 

1"

520

350

285

245

215

195

170

150

120

 

 

 

 

 

 

 

 

 

 

1 1/4"

1050

730

590

500

440

400

350

305

250

 

 

 

 

 

 

 

 

 

 

1 1/2”

1600

1100

890

760

670

610

530

460

380

Note: Maximum pipe capacity in ft3/hr is based on a 0.60 specific gravity

gas at a pressure of 0.5 psig and a 0.3" WC pressure drop.

Table 5 - Equivalent Pipe Length Chart

Nominal

 

Type of Pipe Fitting

 

Iron

90°

Tee

Gate Valve

Gas Cocks

Pipe

(branch flow)

(full port)

 

 

Size

Equivalent length of pipe fittings in feet

3/4"

2.06

4.12

0.48

1.25

 

 

 

 

 

 

 

1"

2.62

5.24

0.61

1.60

 

 

 

 

 

 

1

1/4"

3.45

6.90

0.81

2.15

 

 

 

 

 

 

1

1/2"

4.02

8.04

0.94

2.50

 

 

 

 

 

 

Whenever the gas supply piping is pressure tested the boiler gas controls must be protected. If the test pressure is equal to, or less than 1/2 psi, 3.5 kPa, isolate the boiler by closing it’s manual shut off valve, see Figure 27. If the test pressure is greater than 1/2 psi, 3.5 kPa, disconnect the boiler and it’s individual shut-off valve from the gas supply piping.

WARNING: Failure to protect the gas valve from excessive pressure can damage the gas valve which can cause a fire or explosion!

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Smith Cast Iron Boilers GT Series manual GAS Supply Piping, Gas Pipe Capacity, Equivalent Pipe Length Chart
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GT Series specifications

Smith Cast Iron Boilers GT Series has become a benchmark in the hydronic heating industry, renowned for its exceptional performance, durability, and efficiency. This series is designed to cater to diverse heating needs, making it a popular choice among both residential and commercial applications.

One of the standout features of the GT Series is its robust cast iron construction. The cast iron sections offer superior thermal mass, allowing for better heat retention and distribution. This characteristic ensures that the boiler operates efficiently, maintaining comfortable temperatures even during extreme cold weather conditions. The engineers at Smith have meticulously designed each section to provide maximum strength and longevity, resulting in a boiler that can withstand the test of time.

The GT Series also incorporates advanced combustion technology. It utilizes a high-efficiency burner that optimizes fuel consumption, resulting in lower operating costs for homeowners and businesses alike. The boiler is engineered to accommodate a variety of fuel types, including natural gas and propane, giving users flexibility in their energy choices. This adaptability not only enhances efficiency but also promotes environmental sustainability by allowing for the use of cleaner fuel sources.

Another notable technology featured in the GT Series is the electronic control system. This system simplifies boiler operation and enhances user convenience. The intuitive interface provides real-time feedback and diagnostics, making it easier for technicians to perform maintenance and troubleshoot any issues that may arise. Additionally, the boiler’s modulating operation adjusts the burner output according to the heating demand, further improving efficiency and comfort.

Moreover, the GT Series is designed with user-friendly installation in mind. Its compact footprint allows for easy integration into existing heating systems, minimizing space requirements. Additionally, the boiler is equipped with convenient access points for maintenance, ensuring that servicing is straightforward and can be performed without extensive downtime.

Lastly, the Smith Cast Iron Boilers GT Series is designed to meet stringent safety and performance standards. Featuring multiple safety controls and systems, it provides peace of mind for users. With a commitment to quality, efficiency, and performance, the GT Series stands out as a leading solution for hydronic heating, catering to the evolving needs of today’s energy-conscious consumers.
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