Straight Bulkhead Union
(BBU)

Designations	Tube O.D	d	Width across flat		t	ℓ1	ℓ	Approx.		Panel Hole
Designations	D	d	H1	H	t	ℓ1	ℓ	L1	L	Drill Size	Max. Thickness
BBU-04	4	2.5	14	12	6.0	25	14	32.5	21.5	10.5	13
BBU-06	6	4	17	14	7.0	32	19	42.5	29.5	12.5	13
BBU-08	8	6	19	17	7.0	32	19	42.5	29.5	14.5	13
BBU-10	10	8	22	19	7.0	32	20	43.5	31.5	16.5	13
BBU-12	12	10	24	22	7.0	32	20	43.5	31.5	18.5	13
BBU-15	15	12	27	27	7.5	37	22	49.5	34.5	22.5	15
BBU-16	16	13	30	30	7.5	37	24	49.5	36.5	24.5	15
BBU-18	18	14	32	32	8.0	39	24	51.5	36.5	26.5	15
BBU-20	20	17	32	36	8.0	39	24	51.5	36.5	28.5	15
BBU-22	22	18	36	36	9.0	39	25	51.5	37.5	30.5	15
BBU-25	25	20	41	41	10.0	39	25	52.5	38.5	35.5	15
BBU-28	28	22	46	46	10.0	41	28	55.0	42	38.5	15
BBU-30	30	25	46	46	10.0	41	28	55.5	42.5	40.5	15
BBU-32	32	26	50	50	11.0	43	30	57.5	44.5	42.5	15
BBU-35	35	28	50	55	11.0	43	30	60.5	47.5	45.5	15
BBU-38	38	32	55	60	12.0	45	31	64.5	50.5	48.5	15
BBU-40	40	32	60	60	12.0	50	37	69.5	56.5	52.5	15
BBU-50	50	40	70	75	12.0	50	43	71.5	64.5	64.5	15
BBU-81	10.5 (1/8")	8	22	19	7.0	32	20	43.5	31.5	16.5	13
BBU-82	13.8 (1/4")	11	27	24	7.5	37	22	49.0	34	20.5	15
BBU-83	17.3 (3/8")	14	32	32	8.0	39	24	51.5	36.5	26.5	15
BBU-84	21.7 (1/2")	18	36	36	9.0	39	25	51.5	37.5	30.5	15
BBU-85	27.2 (3/4")	22	46	46	10.0	41	28	55.0	42	38.5	15
BBU-86	34.0 (1")	28	50	55	11.0	43	30	60.5	47.5	45.5	15
BBU-87	42.7 (1 1/4")	34	65	65	12.0	50	40	70.5	60.5	56.5	15
BBU-88	48.6 (1 1/2")	40	70	75	12.0	50	43	71.5	64.5	64.5	15