Type O and OA Diaphragms

General Description

Type O Diaphragm

This type of diaphragm has no flange. An O-ring is molded to the bottom of the sidewall. Unlike the other types of diaphragms, the Type O is put into convolution by folding the sidewall back onto itself. The bead is then squeezed into a groove machined into the bonnet half of the hardware. This type enables the greatest reduction in hardware diameter, while keeping a full stroke potential.

Type OA Diaphragm

This diaphragm type is second generation to the Type O. It fits into identical hardware. It differs from the Type O in that its sidewall attaches to the inside diameter of the O-ring and the fabric is on the outside, requiring the head corner radius to be inverted for installation. The Type OA tends to be easier to install but basically the difference is a personal preference.

Dimensions and Tolerances

Type O and OA Figure 1

	Inches	mm	Inches	mm	Inches	mm
Cylinder Diameter	1.00-2.50	25-64	2.51-4.00	64-102	4.01-8.00	102 & up
Bead Diameter	.121	3.07	.151	3.84	2.42	6.15
Convolution Width	.094	2.39	.156	3.96	2.50	6.35
Flash Projection	.020 x .020 Max.	0.51 x .0.51 Max.	.030 x .030 Max.	0.76 x 0.76 Max.	.040 x .040 Max.	1.02 x 1.02 Max.
Wall Gauge	.017	0.43	.024	0.61	.035	0.89
Piston Radius	.063	1.60	.094	2.39	.125	3.18
Piston Diameter	Cyl. Diam. less .188	Cyl. Diam. less 4.78	Cyl. Diam. less .313	Cyl. Diam. less 7.95	Cyl. Diam. less .500	Cyl. Diam. less 12.70

Hardware Design

Type O and OA Figure 2

Cylinder Diameter		Bead Groove Width = W		Bead Groove Height = H		Flange & Piston Corner Radii = R1 & R2		Lip Radius = R3		Lip Height = L
(Inches)	(mm)	(Inches)	(mm)	(Inches)	(mm)	(Inches)	(mm)	(Inches)	(mm)	(Inches)	(mm)
1.00-2.50	25-64	.125	3.18	.096	2.43	.063	1.60	.025	0.63	.100	2.54
2.51-4.00	64-102	.156	3.96	.122	3.10	.094	2.39	.032	0.81	.130	3.30
4.01-8.00	102-205	.250	6.35	.196	4.98	.125	3.18	.045	1.14	.204	5.18
8.01 and up	205 and up	.250	6.35	.196	4.98	.125	3.18	.045	1.14	.190	4.83

Available Sizes

Dia•Com Part No.	Cylinder Diameter		Piston Diameter		Height		Gauge Approx.		Convolution Width		Effective Pressure Area		Maximum Half-Stroke
Dia•Com Part No.	(Inches)	(mm)	(Inches)	(mm)	(Inches)	(mm)	(Inches)	(mm)	(Inches)	(mm)	(Inches)	*	(Inches)	(mm)
O-137-87	1.37	35	1.19	30	0.87	22	.017	0.43	.090	2.3	1.29	8.3	0.52	13.2
O-150-62	1.50	38	1.31	33	0.62	16	.017	0.43	.095	2.4	1.55	10.0	0.29	7.4
O-150-94	1.50	38	1.31	33	0.94	24	.017	0.43	.095	2.4	1.55	10.0	0.61	15.5
O-175-144	1.75	44	1.56	40	1.44	37	.017	0.43	.095	2.4	2.15	13.9	1.13	28.7
O-180-144	1.80	46	1.38	35	1.44	37	.025	0.64	.210	5.3	1.98	12.8	0.80	20.3
O-187-150	1.87	47	1.69	43	1.50	38	.017	0.43	.090	2.3	2.49	16.0	1.15	29.2
O-200-162	2.00	51	1.81	46	1.62	41	.017	0.43	.095	2.4	2.85	18.4	1.27	32.3
O-200-200	2.00	51	1.87	47	2.00	51	.017	0.43	.065	1.7	2.94	19.0	1.64	41.7
O-250-200	2.50	64	2.31	59	2.00	51	.017	0.43	.095	2.4	4.54	29.3	1.65	41.9
O-275-112	2.75	70	2.44	62	1.12	28	.024	0.61	.155	3.9	5.29	34.1	0.57	14.5
O-400-238	4.00	102	3.69	94	2.38	60	.035	0.89	.155	3.9	11.61	74.9	1.83	46.5
O-500-312	5.00	127	4.50	114	3.12	79	.035	0.89	.250	6.4	17.71	114.3	2.28	57.9
O-600-440	6.00	152	5.50	140	4.40	112	.035	0.89	.250	6.4	25.95	167.4	3.56	90.4

OA-50-53	.50	13	0.36	9	0.53	13	.015	0.38	.070	1.8	0.15	0.9	0.34	8.6
OA-75-85	0.75	19	0.55	14	0.85	22	.017	0.43	.100	2.5	0.33	2.1	0.46	11.7
OA-106-145	1.06	27	0.94	24	1.45	37	.017	0.43	.060	1.5	0.79	5.1	1.12	28.4
OA-112-69	1.12	28	0.94	24	0.69	18	.017	0.43	.090	2.3	0.83	5.4	0.33	8.4
OA-137-53	1.37	35	1.19	30	0.53	13	.017	0.43	.090	2.3	1.29	8.3	0.17	4.3
OA-187-197	1.87	47	1.69	43	1.97	50	.017	0.43	.090	2.3	2.49	16.0	1.69	42.9
OA-200-69	2.00	51	1.81	46	0.69	18	.017	0.43	.095	2.4	2.85	18.4	0.33	8.4
OA-225-137	2.25	57	2.06	52	1.37	35	.018	0.46	.095	2.4	3.65	23.5	1.01	25.7
OA-283-160	2.83	722	2.52	64	1.60	41	.024	0.61	.155	3.9	5.62	36.2	1.09	27.7
OA-462-350	4.62	117	4.00	102	3.50	89	.035	0.89	.310	7.9	14.58	94.1	2.86	72.6
OA-475-225	4.75	121	4.25	108	2.25	57	.017	0.43	.250	6.4	15.90	102.6	1.22	31.0
*Metric effective pressure area shown in square centimeters.

Dia•Com is a leading international provider of innovative, cost-effective molded diaphragm solutions critical to the operation of essential systems and equipment in industrial, automotive, aerospace, medical instrumentation, and food and water processing applications. The company's reputation for excellence is based on superior quality in the design, manufacture and application of its high-performance, state-of-the-art, fabric-reinforced and homogeneous elastomeric rubber seals. Our custom engineered solutions are found in many products today, including diaphragm pumps, rubber seals, pneumatic diaphragm pumps, high pressure diaphragm pumps, viton gaskets, diaphragm carburetor, diaphragm pressure gauges, diaphragm vacuum pumps, diaphragm air compressors, diaphgram fuel pumps and diaphragm metering pumps.