AMERICA’s Sheet Metal Source

Since 1981

Duct Connectors

Duct connectors are an essential part of the system. Transverse connections are the primary location for sealing the duct system from leakage, so the choice of duct connection method has a large impact on the quality of an installation, as well as the cost of installing the system.

At Spiral Pipe of Texas, we offer a wide variety of duct connection products — from traditional methods and 3rd-party products, as well as a few proprietary products we have developed ourselves. We don’t just make “ducts”, we make “duct systems”, and connectors are an essential part.

Single-Wall SPOT Flanges

SPOT Flanges are an economical option for joining spiral round and flat oval pipe and fittings where the size or an installer preference requires a flanged connection. They are roll-formed from 18-gauge galvanized material, then factory mounted on our spiral pipe and fittings by spot-welding and sealing. Field connections are made using neoprene gaskets or butyl tape placed between flanges, then screwed together on 6-inch centers.

Optional materials are available. Please contact the nearest Spiral Pipe of Texas representative for more information.



Double-Wall SPOT Flanges

SPOT Flanges are an economical option for joining double-wall round and flat oval spiral pipe and fittings where the size or an installer preference requires a flanged connection. They are roll-formed from 18-gauge galvanized material, then factory mounted on our spiral pipe and fittings by spot-welding and sealing. A secondary metal nosing is inserted into the inner shell, bridging the gap between the inner and outer shell while isolating the insulation media from the airstream. Field connections are made using neoprene gaskets or butyl tape placed between flanges, then screwed together on 6-inch centers.

Optional materials are available. Please contact the nearest Spiral Pipe of Texas representative for more information.

SPOT Triple-Seal Gasket System

The Triple-Seal Gasket System from Spiral Pipe of Texas is engineered to produce a sealed duct system without the need to apply mastic sealants at duct joints. The TPV Uniprene gaskets are factory-installed on couplings and fitting ends. When the couplings and fittings are slipped into the spiral duct ends in the field, the resulting connections meet the requirements of ASHRAE Seal Class A — without the need for additional mastic sealant. Properly installed, duct systems using the SPOT Triple-Seal Gasket System can meet a Leakage Class 2 or better.

Why should you use a gasketed duct system? Current energy codes (ASHRAE Standard 90.1-2013) require all ducts to be sealed. Although leakage testing is not always required, ducts are still expected to perform to a Leakage Class 4 or better.

After all, what’s the point in sealing a duct system if you’re not fixing most of the leaks? Gasketed duct systems save the installer all the time it would have taken to apply mastic sealants at each transverse connection. The Triple-Seal Gasket System gives you the assurance of a proper seal that will perform to the new tighter leakage classes.

Some installers assume that exposed duct systems do not need to be sealed. That is incorrect for a number of reasons. First of all, there is no exemption for exposed duct systems in the energy codes. Second, the idea that “the air is leaking into the space it’s supposed to be going to” is based on some very faulty logic. The purpose of ducting air into a room is not to “fill the box” with air. It is to transport air to the people or equipment that occupy the room.

The outlets on an exposed duct system are designed to project the air from the duct system to these people and equipment as efficiently as possible, and system volume should be designed around getting a certain volume to them. Air that does not reach the occupied space — rather from “scatter” or leakage — is pulled into the return air system. Fan volume must be increased to compensate for that air, resulting in larger ducts and equipment, as well as increased energy costs. Third, leaking duct joints can produce noise, something you really don’t want from an exposed duct system.

Finally, unsealed duct joints in an exposed duct system will, over time, turn into a dusty, dirty duct system. We’ve all seen the black streaks radiating from the joints of unsealed exposed ducts, and it’s a problem that should have been avoided through sealing. SPOT Triple-Seal Gasket Systems are perfect for your exposed round duct applications! You get sealed duct joints — but without the look of mastic smeared over the duct joints.

The SPOT Triple-Seal Gasket System is available for round duct — single-wall, lined and double-wall construction. The product is available in diameters of 6” through 40”. Consult the factory for additional sizes and applications.

Angle Ring Specifications

Order SizeInside Diameter I.D.Outside Diameter O.D.Width WHeight    HThickness TBolt Holes Centers B.C.Hole SizeNumber of HolesApprox Weight Lbs.
3"3 1/16"5 1/16"1"7/8"10 GA4 5/16"9/32"60.70
4"4 1/16"6 1/16"1"15/16"10 GA5 5/16"9/32"60.85
5"5 1/16"7 1/16"1"1"10 GA6 5/16"9/32"61.18
6"6 3/32"8 1/8"1"1"10 GA7 5/16"9/32"61.38
7"7 1/8"9 1/8"1"1"1/8"8 7/16"3/8"61.73
8"8 1/8"10 5/8"1"1"1/8"9 7/16"3/8"61.90
9"9  1/8"11 5/8"1 1/4"1 1/4"1/8"10 5/8"7/16"62.55
10"10 1/8"12 9/16"1 1/4"1 1/4"1/8"11 13/16"7/16"63.05
11"11 1/8"13 9/16"1 1/4"1 1/4"1/8"12 3/4"7/16"63.25
12"12 1/8"15 1/16"1 1/2"1 1/2"1/8"14"7/16"83.88
13"13 1/8"16 1/16"1 1/2"1 1/2"1/8"15"7/16"84.25
14"14 1/8"17 1/16"1 1/2"1 1/2"1/8"16”7/16"84.75
15"15 1/8"18 1/16"1 1/2"1 1/2"3/16"17"7/16"87.25
16"16 1/8"19 3/16"1 1/2"1 1/2"3/16"18"7/16"88.00
17"17 1/8"20 3/16"1 1/2"1 1/2"3/16"19"7/16"88.25
18"18 1/8"22 3/16"1 1/2"1 1/2"3/16"20"7/16"88.50
19"19 1/8"22 3/16"1 1/2"1 1/2"3/16"20 3/4"7/16"128.75
20"20 1/8"23 3/16"1 1/2"1 1/2"3/16"21 3/4"7/16"129.50
21"21 1/8"24 3/16"1 1/2"1 1/2"3/16"22 3/4"7/16"1210.25
22"22 1/8"25 3/16"1 1/2"1 1/2"3/16"23 3/4"7/16"1210.75
23"23 1/8"26 3/16"1 1/2"1 1/2"3/16"24 7/8"7/16"1211.25
24"24 1/8"27 3/16"1 1/2"1 1/2"3/16"25 7/8"7/16"1211.50
25"25 1/8"28 3/16"1 1/2"1 1/2"3/16"26 7/8"7/16"1612.00
26"26 1/8"30 1/8"2"2"3/16"23 3/8"7/16"1616.75
27"27 1/8"31 1/8"2"2"3/16"29 3/8"7/16"1617.38
28"28 1/8"32 1/8"2"2"3/16"30 3/8"7/16"1618.00
29"29 1/8"33 1/8"2"2"3/16"31 3/8"7/16"1618.75
30"30 1/8"34 1/8"2"2"3/16"32 3/8"7/16"1619.50
31"31 1/8"35 1/8"2"2"3/16"33 3/8"7/16"1620.38
32"32 1/8"36 1/8"2"2"3/16"34 3/8"7/16"1620.75
33"33 1/8"37 1/8"2"2"3/16"35 3/8"7/16"1621.25
34"34 1/8"38 1/8"2"2"3/16"36 3/8"7/16"1622.00
35"35 1/8"39 1/8"2"2"3/16"37 3/8"7/16"1622.50
36"36 1/8"40 1/8"2"2"3/16"38 3/8"7/16"1623.00
37"37 1/8"41 1/8"2"2"3/16"39 3/8"7/16"2423.75
38"38 1/8"42 1/8"2"2"3/16"40 3/8"7/16"2424.50
39"39 1/8"43 1/8"2"2"3/16"41 3/8"7/16"2425.00
40"40 1/8"44 1/8"2"2"3/16"42 3/8"7/16"2425.75
41"41 1/8"45 1/8"2"2"3/16"43 3/8"7/16"2426.13
42"42 1/8"46 1/8"2"2"3/16"44 3/8"7/16"2426.50
43"43 1/8"47 1/8"2"2"3/16"45 3/8"7/16"2427.38
44"44 1/8"48 1/8"2"2"3/16"45 3/8"7/16"2428.00
45"45 1/8"49 1/8"2"2"3/16"47 3/8"7/16"2428.63
46"46 1/8"50 1/8"2"2"3/16"48 3/8"7/16"2429.00
47"47 1/8"51 1/8"2"2"3/16"49 3/8"7/16"2429.88
48"48 1/8"52 1/8"2"2"3/16"50 3/8"7/16"2430.75
49"49 1/8"53 1/8"2"2"3/16"51 3/8"7/16"2431.50
50"50 1/8"54 1/8"2"2"3/16"52 3/8"7/16"2432.00
51"51 1/8"55 1/8"2"2"3/16"53 3/8"7/16"2432.75
52"52 1/8"56 1/8"2"2"3/16"54 3/8"7/16"2433.38
53"53 1/8"57 1/8"2"2"3/16"55 3/8"7/16"2434.00
54"54 1/8"58 1/8"2"2"3/16"56 3/8"7/16"2434.75
55"55 1/8"59 1/8"2"2"3/16"57 3/8"7/16"3235.38
56"56 1/8"60 1/8"2"2"3/16"58 3/8"7/16"3236.00
57"57 1/8"61 1/8"2"2"3/16"59 3/8"7/16"3236.50
58"58 1/8"62 1/8"2"2"3/16"60 3/8"7/16"3237.00
59"59 1/8"63 1/8"2"2"3/16"61 3/8"7/16"3237.75
60"60 1/8"64 1/8"2"2"3/16"62 3/8"7/16"3238.50
61"61 1/8"65 1/8"2"2"3/16"63 3/8"7/16"3239.00
62"62 1/8"66 1/8"2"2"3/16"64 3/8"7/16"3239.75
63"63 1/8"67 1/8"2"2"3/16"65 3/8"7/16"3240.38
64"64 1/8"68 1/8"2"2"3/16"66 3/8"7/16"3241.00
65"65 1/8"69 1/8"2"2"3/16"67 3/8"7/16"3241.75
66"66 1/8"70 1/8"2"2"3/16"68 3/8"7/16"3242.38
67"67 1/8"71 1/8"2"2"3/16"69 3/8"7/16"3243.00
68"68 1/8"72 1/8"2"2"3/16"70 3/8"7/16"3243.50
69"69 1/8"73 1/8"2"2"3/16"71 3/8"7/16"3244.25
70"70 1/8"74 1/8"2"2"3/16"72 3/8"7/16"3244.88
71"71 1/8"75 1/8"2"2"3/16"73 3/8"7/16"3245.50
72"72 1/8"76 1/8"2"2"3/16"74 3/8"7/16"3246.25

*** Angle rings listed above are standard stock construction. Heavier construction and higher hole counts may be required for many applications, including industrial systems, negative pressure and high positive pressures.

Angle Ring Attachment


Available Materials

Carbon Steel (Black Iron) — standard
Hot Dipped Galvanized (ASTM A123)
Zinc Electroplated (ASTM B633)
Stainless Steel — 304 & 316
Aluminum

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