Engineering Calculations for Adjustable Support Bridge Assemblies

(For Rubber EcoCurbs)

Subject:
Limited Engineering Calculations for
Adjustable Support Bridge Assemblies
as manufactured by
Advanced Support Products, Inc.
Date: November 7, 2000

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Report done by:
M & Q Engineering, Inc.
1801 Kingwood Drive, Suite 250
Kingwood, Texas 77339

(fig. 1) Pipe Hanger Design Uplift Resistance
(figs. 2, 3 & 4) Typical Roof Loads Due to Gravity Bearing Stresses
(fig. 2) Minimum Pipe Hanger Assembly
(fig. 3) Medium Pipe Hanger Assembly
(fig. 4) Maximum Pipe Hanger Assembly
(fig. 5) Product Information – Standard Bases

The data utilized for these calculations was obtained from Unistrut for the structural assemblies and from Ginnell for the pipe hangers. The information for the rubber molded bases was obtained from Advanced Support Products, Inc. product Data.

The calculations performed are limited and only indicated the static loads that would be exerted on a roof deck by the support assemblies including standard sections of single or multiple lengths of pipe conveying natural gas and water.

The piping and hanger assemblies in this report are considered "dead" loads and should be taken into account during structural design of the roof system. The hanger assembly loads in the attached tables are intended to be used by the structural designer and provide the information required to properly evaluate the complete roof system.

The products and their characteristics were tested by Advanced Support Products, Inc. and represent the basis for our calculations. Roof membrane system analysis as well as long term performance of the products was not part of the calculation process. The following assumptions were taken into account for the calculations:

Placement of load on pipe supports was assumed to be symmetrical
Performance of the products at other than static loading was not part of the calculation process.
Hanger assemblies and piping were assumed to be placed on a horizontal surface and pipe supports are normal to pipe.

Conclusions:

Based on our inspection and analysis of the product design, the load capacity values at each point of support of the pipe hanger assemblies, including the weight of piping are all less than the maximum allowable stresses for typical roof deck insulations types currently in use (5psi maximum). Therefore, the Adjustable Support Bridge Assemblies as manufactured by Advanced Support Products, Inc. meet Factory Mutual Research Corporation's recommendation that the design uplift resistance for base should not exceed half of the ultimate design uplift resistance of the roof cover system. The uplift resistance therefore, is dependent on the uplift rating of the roof cover system.

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(fig. 1) Pipe Hanger Design Uplift Resistance

Advanced Support Products, Inc. Uplift Resistance
Base Size	FM Wind Uplift Rating
	60	90	150	180
12” x 12”	30	45	75	90
7.25” x 6”	9.1	13.1	22.7	27.2
7.25” x 9”	13.6	20.4	34.0	65.3
7.25” x 13”	19.6	29.5	49.1	58.9

(fig. 2) Typical Roof Loads Due to Gravity Bearing Stresses

(Minimum Pipe Hanger Assembly)

Curb Area:	348 sq.in.
Curb Weight:	32.0 lbs.
Frame Weight:	29.0 lbs.
Hanger Weight:	08.0 lbs.
Assembly Weight:	69.0 lbs. 1 pipe 77.0 lbs. 2 pipes

Pipe Diameter	Quantity	Pipe Contents	Pipe Support Spacing
			6 feet	8 feet	10 feet
4 inch	1	water	167.0 lbs	199.0 lbs.	229.0 lbs
			0.48 psi	0.57 psi	0.66 psi
	2	water	273.0 lbs	337.0 lbs	397.0 lbs
			0.78 psi	0.97 psi	1.14 psi
6 inch	1	water	259.0 lbs	319.0 lbs	379.0 lbs
			0.74 psi	0.92 psi	1.09 psi
	2	water	457.0 lbs	577.0 lbs	697.0 lbs
			1.31 psi	1.66 psi	2.00 psi

The bearing stresses indicated above reflect utilization of an assembly consisting of 4 each CCB 1806 Brace Bridges, 4 each CL 18 Channel Legs and 2 each ACB 18 Adjustable Cross Bars.

(fig. 3) Typical Roof Loads Due to Gravity Bearing Stresses

(Medium Pipe Hanger Assembly)

Curb Area:	522 sq.in.
Curb Weight:	48.0 lbs.
Frame Weight:	29.0 lbs.
Hanger Weight:	08.0 lbs.
Assembly Weight:	85.0 lbs. 1 pipe 93.0 lbs. 2 pipe 101.0 lbs 3 pipes

Pipe Diameter	Quantity	Pipe Contents	Pipe Support Spacing
Pipe Diameter	Quantity	Pipe Contents	6 feet	8 feet	10 feet
4 inch	1	Gas lbs psi	150	171	195
		Gas lbs psi	0.29	0.33	0.37
		Water lbs psi	183	215	245
		Water lbs psi	0.35	0.41	0.47
	2	Gas lbs psi	223	265	313
		Gas lbs psi	0.43	0.51	0.60
		Water lbs psi	289	353	413
		Water lbs psi	0.55	0.68	0.79
	3	Gas lbs psi	296	359	431
		Gas lbs psi	0.57	0.69	0.83
		Water lbs psi	395	491	581
		Water lbs psi	0.76	0.94	1.11
6 inch	1	Gas lbs psi	195	235	275
		Gas lbs psi	0.37	0.45	0.53
		Water lbs psi	275	335	395
		Water lbs psi	0.53	0.64	0.76
	2	Gas lbs psi	313	393	473
		Gas lbs psi	0.60	0.75	0.91
		Water lbs psi	473	593	713
		Water lbs psi	0.91	1.14	1.37
	3	Gas lbs psi	431	551	671
		Gas lbs psi	0.83	1.06	1.29
		Water lbs psi	671	851	1031
		Water lbs psi	1.29	1.63	1.98

The bearing stresses indicated above reflect utilization of an assembly consisting of 4 each CCB 1806 Brace Bridges, 4 each CL 18 Channel Legs and 2 each ACB 18 Adjustable Cross Bars.

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(fig. 4) Typical Roof Loads Due to Gravity Bearing Stresses

(Maximum Pipe Hanger Assembly)

Curb Area:	754 sq.in.
Curb Weight:	80.0 lbs.
Frame Weight:	29.0 lbs.
Hanger Weight:	08.0 lbs.
Assembly Weight:	117.0 lbs. 1 pipe 125.0 lbs. 2 pipe 133.0 lbs 3 pipes

Pipe Diameter	Quantity	Pipe Contents	Pipe Support Spacing
Pipe Diameter	Quantity	Pipe Contents	6 feet	8 feet	10 feet
4 inch	1	Gas lbs psi	182	203	227
		Gas lbs psi	0.29	0.27	0.30
		Water lbs psi	215	247	277
		Water lbs psi	0.29	0.33	0.37
	2	Gas lbs psi	255	297	345
		Gas lbs psi	0.34	0.39	0.46
		Water lbs psi	321	385	445
		Water lbs psi	0.43	0.51	0.59
	3	Gas lbs psi	328	391	463
		Gas lbs psi	0.44	0.52	0.61
		Water lbs psi	427	523	613
		Water lbs psi	0.57	0.69	0.81
6 inch	1	Gas lbs psi	195	267	307
		Gas lbs psi	0.37	0.35	0.41
		Water lbs psi	275	367	427
		Water lbs psi	0.53	0.49	0.57
	2	Gas lbs psi	313	425	505
		Gas lbs psi	0.60	0.56	0.91
		Water lbs psi	473	625	745
		Water lbs psi	0.91	0.83	0.99
	3	Gas lbs psi	431	583	703
		Gas lbs psi	0.83	0.77	0.93
		Water lbs psi	671	883	1063
		Water lbs psi	1.29	1.17	1.41
8 inch	1	Gas lbs psi	287	347	407
		Gas lbs psi	0.38	0.46	0.54
		Water lbs psi	417	517	617
		Water lbs psi	0.55	0.69	0.82
	2	Gas lbs psi	465	585	705
		Gas lbs psi	0.62	0.78	0.94
		Water lbs psi	725	925	1125
		Water lbs psi	0.96	1.23	1.49
10 inch	1	Gas lbs psi	357	437	527
		Gas lbs psi	0.47	0.58	0.70
		Water lbs psi	567	717	867
		Water lbs psi	0.75	0.95	1.15
	2	Gas lbs psi	605	765	945
		Gas lbs psi	0.80	1.01	1.25
		Water lbs psi	1025	1325	1625
		Water lbs psi	1.36	1.76	2.16
12 inch	1	Gas lbs psi	417	517	617
		Gas lbs psi	0.55	0.69	0.82
		Water lbs psi	707	907	1107
		Water lbs psi	0.94	1.20	1.47

The bearing stresses indicated above reflect utilization of an assembly consisting of 4 each CCB 1806 Brace Bridges, 4 each CL 18 Channel Legs and 2 each ACB 18 Adjustable Cross Bars.

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(fig. 5) Product Information - Standard Bases (Rubber)

	Minimum Base	Medium Base	Maximum Base
Size (inches)	7.25 x 6	7.25 x 9	7.25 x 13
Weight	4 lbs.	6 lbs.	10 lbs.
Area	43.50 sq.in.	65.25 sq.in.	94.25 sq.in.
Area per Support Bridge
4 bases	174 sq.in.	261 sq.in.	377 sq.in.
Area per Pipe Section
8 bases	348 sq.in.	522 sq.in.	754 sq.in.

Toolkit

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