Armstrong 6000 Series heavy duty steam and liquid coils are designed to accommodate the service requirements of demanding industrial installations. They provide a complete range of solutions for heating, cooling, and process drying applications. Built with enough material at the tube-to-header joints to ensure strength, these coils survive the rigors of high pressures, high temperatures, and corrosive conditions. All Armstrong coils are of mono-metallic design, meaning all wetted parts are made of the same materials, which precludes the likelihood of galvanic corrosion often experienced in coils made of dissimilar materials.

The base material found in the 6000 Series coils is steel, with a minimum wall thickness of .109" for steam and liquid coils, affording both strength and internal corrosion resistance. The coils are always of welded construction, providing the most reliable method of connecting the tubes to the headers. Each coil is tested during construction, and the completed unit is hydrostatically tested to not less than 1.3 times the design pressure.

Fin Designs

The effective heat transfer of a coil is based on fin pitch, fin height, fin material, and method of attachment. Armstrong offers multiple fin designs to combat dirt buildup and maximize heat transfer.

Keyfin

The keyfin is the standard design for Armstrong’s most popular coils. Keyfin coils are manufactured by forming a helical groove in the tube surface, winding the fin into the groove and peening the displaced metal from the groove against the fin. This ensures a tight fit between the fin and the tube, providing efficient operation over wide temperature ranges. Keyfin is the superior design for dissimilar fin and tube materials.

L Fin

The L fin has a "foot" at its base and is tension wound on knurled tube material. The L-shaped base provides a large contact area between the tube and the fin, ensuring effective, long-lasting heat transfer. The L fin is recommended when tubes and fins are of the same material.

Overlap L Fin

The overlap L fin is simply an L fin with an extended base. Each fin overlaps the foot of the previous fin, completely covering the tube surface. The overlap technique makes it possible to create a completely aluminumized coil for applications where exposed steel would be vulnerable to corrosion.

Construction Features

Component	Type	Specifications
Carbon Steel Tubes	Standard	12 ga A-214 ERW
	Optional	10 ga A-214 ERW; 12 ga A-179 seamless; 10 ga A-179 seamless
Carbon Steel Pipes	Optional	Sch 80 seamless; A-106 Gr 'B'
Stainless Steel Tubes	Standard	14 ga (1" OD) 12 ga (1-1/2" OD) A-249 type 304L
	Optional	14 ga (1" OD) 12 ga (1-1/2" OD) A-249 type 316L
Steel Fins	Standard	0.024" thick on 3/4" NPS pipes & 1" OD tubes; 0.036" thick on 1-1/2" OD tubes & 1" NPS & larger pipe
Aluminum Fins	Standard	0.020" thick on all tube sizes; 0.016" thick on 1" OD
	Optional	0.030" heavy keyfin 1" & 1-1/2" OD steel and stainless steel tube
Stainless Steel Fins	Standard	0.020" thick type 304 & 316 on all sizes
Copper Fins	Standard	0.016" thick on all sizes
Connections	Steel	Sch 80 (screwed), Sch 40 (flanged)
	Stainless Steel	Sch 40 (screwed), Sch 10 (flanged)
Headers	All	Welded construction, same material as tubing
Casing	Galvanized Steel	Min 12 ga for depth 7-1/2" and over; Min 14 ga for depth under 7-1/2"
	Stainless Steel	14 ga type 304 & 316 for all depths (Optional)
	Aluminum	12 ga for all depths (Optional)

Design and Testing

Standard design pressure for steel coils is 300 psig @ 650°F, stainless steel coils 300 psig @ 500°F. Hot oil coil: 250 psig @ 750°F. All coils are tested hydrostatically to at least 1.3 times the working pressure with a standard testing pressure at 450 psig on steel & stainless steel steam coils. Coils are available with ASME Section VIII, Division I, "U" stamps or CRN approval.

Model Number Breakdown

Example: H – S 2 A 09 – Q 08 – 30 x 72 x 6

• Type of Coil: L = Liquid, S = Standard, C = Centifeed, T = Tandem (Opposite-End), P = Tandem (Same-End)
• Orientation: H = Horiz. Tubes/Horiz. Air, V = Vert. Tubes/Horiz. Air, D = Horiz. Tubes/Vert. Down Air, U = Horiz. Tubes/Vert. Up Air
• Rows Deep: Number of passes (Liquid) or Hand of coil (Tandem Steam)
• Fin Type: A = Aluminum Keyfin (.020"), B = Aluminum Heavy Keyfin (.030"), D = Aluminum G Fin (.020"), E = Aluminum Overlap L Fin (.020"), F = Copper Keyfin (.016"), G = Steel L Fin, H = Steel G Fin (.024"), J = 304 SS L Fin (.020"), K = 316 SS L Fin (.020"), U = Aluminum Keyfin (0.016”)
• Fins Per Inch (FPI): e.g., 09
• Pipe/Tube Type: N = Sch 40 Seamless Steel Pipe, P = Sch 80 Seamless Steel Pipe, Q = 12 ga Steel Tube, R = 10 ga Steel Tube, S = 12 ga Steel Tube (SMLS), T = 10 ga Steel Tube (SMLS), U = Sch 10 304L SS Pipe, V = Sch 10 316L SS Pipe, W = 14 ga 304L SS Tube, X = 12 ga 304L SS Tube, Y = 14 ga 316L SS Tube, Z = 12 ga 316L SS Tube
• Dimensions: Casing Depth x Casing Length x Casing Width (Inches)

Installation and Operation Guidelines

Successful operation and a long, trouble-free service life depend on proper installation, trapping, and venting.

• Support coils and piping individually to prevent undue strains on the steam and condensate connections. Use swing joints or flexible connections.
• Install a drip trap prior to the coils (and before a control valve) to prevent the introduction of condensate.
• Install strainers with blowdown valves before all control valves and traps.
• Vent non-condensable gases individually on each coil to ensure maximum heat transfer and minimum internal corrosion.
• Trap all coils individually. Use only traps such as the inverted bucket or float and thermostatic which drain continuously.
• To provide maximum freeze protection, maintain a minimum steam pressure of 5 psig to coils exposed to air temperature below 40°F (5°C).

Recommended Piping Practices for Steam Heating Coils

Notes on Piping Practices:

1. 24" minimum if safety drain is used.
2. Safety drain is used if steam supply is modulated and the condensate system is pressurized or overhead.
3. The air vent may be either an orifice bleed or a thermostatically operated element.
4. The main trap may be either an Inverted Bucket or a Float & Thermostatic type depending upon the service conditions.
5. Overhead condensate return.
6. Required only on a modulated system.