MAXIMUM DEPTHS OF COVER

for Minimum Pressure Classes of Ductile Iron Pipe ANSI/AWWA C151/A21.51

This table tabulates the maximum depth of cover for the five types of laying conditions, along with corresponding nominal wall thickness and maximum rated working pressure, all for minimum pressure classes of ductile iron pipe. Taken from the table that follows, it is offered as a convenience for quickly checking the capabilities of minimum pressure classes of ductile iron pipe under a given set of conditions.

For the majority of internal pressure and external loading conditions, minimum pressure classes are more than adequate and possess substantial safety factors.

Size (in.)	Pressure Class	Thickness (in.)	Laying Conditions Maximum Depth of Cover in Feet
Size (in.)	Pressure Class	Thickness (in.)	Type 1	Type 2	Type 3	Type 4	Type 5
4	350	0.25	53	61	69	85	100
6	350	0.25	26	31	37	47	65
8	350	0.25	16	20	25	34	50
10	350	0.26	11	15	19	28	45
12	350	0.28	10	15	19	28	44
14	250	0.28	-	11	15	23	36
16	250	0.3	-	11	15	24	34
18	250	0.31	-	10	14	22	31
20	250	0.33	-	10	14	22	30
24	200	0.33	-	8	12	17	25
30	150	0.34	-	-	9	14	22
36	150	0.38	-	-	9	14	21
42	150	0.41	-	-	9	13	20
48	150	0.46	-	-	9	13	20
54	150	0.51	-	-	9	13	20
60	150	0.54		5	9	13	20
64	150	0.56		5	9	13	20

MAXIMUM DEPTHS OF COVER FOR ALL PRESSURE CLASSES

Ductile Iron Pipe ANSI/AWWA C151/A21.51

This table lists maximum depths of cover for the five types of laying conditions for all standard pressure classes; also tabulated are the corresponding nominal wall thickness and maximum rated working pressure. (Note: Although not listed in the following table, ductile iron pipe for working pressures higher than 350 psi is available. Consult MSABEK regarding specific conditions involved.)

Size (in.)	Pressure Class psi	Nominal Thickness (in.)	Laying Conditions Maximum Depth of Cover in Feet
Size (in.)	Pressure Class psi	Nominal Thickness (in.)	Type 1	Type 2	Type 3	Type 4	Type 5
4	350	0.25	53	61	69	85	100
6	350	0.25	23	31	37	47	65
8	350	0.25	16	20	25	34	50
10	350	0.26	11	15	19	28	45
12	350	0.28	10	15	19	28	44
14	250	0.28		11	15	23	36
14	300	0.3		13	17	26	42
14	350	0.31		14	19	27	44
16	250	0.31		11	15	24	34
16	300	0.32		13	17	26	39
16	350	0.34		15	20	28	44
18	250	0.31		10	14	22	31
18	300	0.34		13	17	26	36
18	350	0.36		15	19	28	41
20	250	0.33		10	14	22	30
20	300	0.36		13	17	26	35
20	350	0.38		15	19	28	38
24	200	0.33		8	12	17	25
24	250	0.37		11	15	20	29
24	300	0.4		13	17	24	32
24	350	0.43		15	19	28	37
30	150	0.34		-	9	14	22
30	200	0.38		8	12	16	24
30	250	0.42		11	15	19	27
30	300	0.45		12	16	21	29
30	350	0.49		15	19	25	33
36	150	0.38		-	9	14	21
36	200	0.42		8	12	15	23
36	250	0.47		10	14	18	25
36	300	0.51		12	16	20	28
36	350	0.56		15	19	24	32
42	150	0.41		-	9	13	20
42	200	0.47		8	12	15	22
42	250	0.52		10	14	17	25
42	300	0.57		12	16	20	27
42	350	0.63		15	19	23	32
48	150	0.46		-	9	13	20
48	200	0.52		8	11	15	22
48	250	0.58		10	13	17	24
48	300	0.64		12	15	19	27
48	350	0.7		15	18	22	30
54	150	0.51		-	9	13	20
54	200	0.58		8	11	14	22
54	250	0.65		10	13	16	24
54	300	0.72		13	15	19	27
54	350	0.79		15	18	22	30
60	150	0.54		5	9	13	20
60	200	0.61		8	11	14	22
60	250	0.68		10	13	16	24
60	300	0.76		13	15	19	26
60	350	0.83		15	18	22	30
64	150	0.56		2	9	13	20
64	200	0.64		8	11	14	21
64	250	0.72		10	13	16	24
64	300	0.8		12	15	19	26
64	350	0.87		15	17	21	29