Type F "Top Hat" Diaphragm

General Description

The Type F is commonly referred to as the “top hat” diaphragm. It exhibits all of the benefits that are associated with rolling diaphragms. These diaphragms have the longest stroke-to-bore ratio, zero spring rate, no breakaway friction, constant effective pressure area, and long life. Some of the drawbacks to Type F diaphragms are additional assembly time required when inverting the top head corner radius during installation, and an inability to withstand reverse pressure.

The flange of the Type F diaphragm is designed to seal like a gasket between the two flat surfaces of the cylinder and bonnet. The outside edge and bolt holes can be cut into any configuration desired. An effective seal should be obtained by compressing the flange area 20-25% thickness.

To extend cycle life and reduce “four-cornering” of the diaphragm, a double taper design may be utilized (see Figure 1). This design reduces the diameter of the bottom end of the diaphragm which minimizes excess material in this area and relieves circumferential compressive stress.

Dimensions and Tolerances

	Inches	mm	Inches	mm	Inches	mm	Inches	mm	Inches	mm
Cylinder Diameter	.25-.99	6-25	1.00-2.50	25-64	2.51-4.00	64-102	4.01-8.00	102-205	8.01 & up	205 & up
Height	See available sizes table
Cylinder Diameter	Tolerances on Cylinder Diameter and Piston Diameter are ± 0.010" per inch (0.254 mm) of diameter but the tolerance will be no less than ± 0.010" (0.254 mm) or greater than ± 0.060" (1.52 mm)
Piston Diameter
Head & Flange Thickness	.015 ± .003	0.38 ± .08	.017 ± .004	0.43 ± 0.10	.024 ± .004	0.61 ± .10	.035 ± .005	0.89 ± 0.13	.045 ± .007	1.14 ± 0.18
Wall Gauge	.015 ± .003	0.38 ± 0.08	.017 ± .004	0.43 ± 0.08	.024 ± .004	0.61 ± 0.10	.035 ± .005	0.89 ± 0.13	.045 ± .007	1.14 ± 0.18
Piston Radius	.094	1.39	.125	3.18	.156	3.96	.250	6.35	.250	6.35
Flange Radius	.031	0.79	.063	1.60	.094	2.39	.125	3.18	.125	3.18
Flange Diameter	Cyl. Diam. ± .750	Cyl. Diam. ± 19.05	Cyl. Diam. ± 1.000	Cyl. Diam. ± 25.40	Cyl. Diam. ± 1.500	Cyl. Diam. + 38.10	Cyl. Diam. ± 2.000	Cyl. Diam. ± 50.80	Cyl. Diam. ± 2.000	Cyl. Diam. ± 50.80

Diaphragm Flange Diameter and Hole Trim Tolerance
Diameter		Size		Position
(Inches)	(mm)	(Inches)	(mm)	(Inches)	(mm)
0-1.00	.0-25.40	± .010	0.25	.010	0.25
1.01-3.00	25.65-76.20	± .020	0.51	.020	0.51
over 3.01	76.45	± .030	0.76	.030	0.76

Hole Spacing for Type F Diaphragms

Type F Figure 3

Max. Working Pressure (P.S.I.)/KPA	(0-50)	0-350	(51-150)	357-1050	(151-300)	1057-2100	(301-500)	2107-3500
Seal Area Minimum Inches/mm	.100	2.54	.150	3.81	.200	5.08	.250	6.35

Hole Spacing

Perforations through the head or the flange should be located so that there is at least 0.100 inches (2.54 mm) minimum between the edges of holes. Also, holes should be located so that there is at least 0.125 inches (3.175 mm) between the edges of a hole and the trim periphery. It is also important to arrange the hole pattern so that the radial distance from the edge of the hole to the start of the blend radius at either the piston head or cylinder clamp flange is at least as far as indicated in the chart above.

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)
F-34-39	0.34	9	0.22	6	0.39	10	.015	0.38	.060	1.5	0.06	0.4	0.17	4.3
F-37-31	0.37	9	0.25	6	0.31	8	.015	0.38	.060	1.5	0.08	0.5	0.09	2.3
F-44-44	0.44	11	0.31	8	0.44	11	.015	0.38	.065	1.7	0.11	0.7	0.21	5.3
F-50-50	0.50	13	0.31	8	0.50	13	.012	0.30	.095	2.4	0.13	0.8	0.12	3.0
F-62-50	0.62	16	0.50	13	0.50	13	.015	0.38	.060	1.5	0.25	1.6	0.28	7.1
F-62-65	0.62	16	0.47	12	0.65	17	.024	0.61	.075	1.9	0.23	1.5	0.47	11.9
F-75-38	0.75	19	0.62	16	0.38	10	.010	0.25	.065	1.7	0.37	2.4	0.12	3.0
F-75-62	0.75	19	0.62	16	0.62	16	.011	0.28	.065	1.7	0.37	2.4	0.36	9.1
F-75-62	0.75	19	0.62	16	0.62	16	.015	0.38	.065	1.7	0.52	3.4	0.36	9.1
F-89-58	0.89	23	0.71	18	0.58	15	.015	0.38	.090	2.3	0.50	3.3	0.21	5.3
F-100-44	1.00	25	0.81	21	0.44	11	.010	0.25	.095	2.4	0.64	4.1	0.06	1.5
F-100-62	1.00	25	0.81	21	0.62	16	.017	0.43	.095	2.4	0.64	4.1	0.24	6.1
F-100-100	1.00	25	0.81	21	1.00	25	.017	0.43	.095	2.4	0.64	4.1	0.62	15.7
F-112-44	1.12	28	0.94	24	0.44	11	.017	0.43	.090	2.3	0.83	5.4	0.07	1.8
F-112-69	1.12	28	0.94	24	0.69	18	.017	0.43	.090	2.3	0.83	5.4	0.32	8.1
F-118-53	1.18	30	0.97	25	0.53	13	.017	0.43	.105	2.7	1.30	8.3	0.22	5.6
F-118-76	1.18	30	0.97	25	0.76	19	.017	0.43	.105	2.7	0.91	5.9	0.45	11.4
F-137-112	1.37	35	1.19	30	1.12	28	.017	0.43	.090	2.3	1.29	8.3	0.75	19.1
F-150-62	1.50	38	1.31	33	0.62	16	.017	0.43	.095	2.4	1.55	10.0	0.24	6.1
F-150-75	1.50	38	1.31	33	0.50	13	.017	0.43	.095	2.4	1.55	10.0	0.37	9.4
F-150-94	1.50	38	1.31	33	0.94	24	.020	0.51	.095	2.4	1.55	10.0	0.56	14.2
F-156-141	1.56	38	1.38	35	1.41	36	.017	0.43	.060	1.5	1.63	10.5	1.04	26.4
F-158-103	1.58	40	1.52	39	1.03	26	.020	0.51	.030	0.8	1.89	12.2	0.90	22.9
F-162-44	1.62	41	1.47	37	0.44	11	.017	0.43	.090	2.3	1.84	11.9	0.07	1.8
F-162-46	1.62	41	1.47	37	0.46	12	.020	0.51	.075	1.9	2.26	12.1	0.07	1.8
F-162-69	1.62	41	1.44	37	0.69	18	.017	0.43	.090	2.3	1.84	11.9	0.32	8.1
F-175-106	1.75	44	1.56	40	1.06	27	.017	0.43	.095	2.4	2.15	13.9	0.68	17.3
F-175-175	1.75	44	1.56	40	1.75	44	.015	0.38	.095	2.4	2.15	13.9	1.37	34.8
F-200-75	2.00	51	1.81	46	0.75	19	.017	0.43	.095	2.4	2.85	18.4	0.37	9.4
F-200-100	2.00	51	1.81	46	1.00	25	.016	0.41	.095	2.4	2.85	18.4	0.62	15.7
F-200-162	2.00	51	1.81	46	1.62	41	.017	0.43	.095	2.4	2.85	18.4	1.24	31.5
F-200-200	2.00	51	1.81	46	2.00	51	.017	0.43	.095	2.4	2.85	18.4	1.62	41.1
F-212-131	2.12	54	1.94	49	1.31	33	.017	0.43	.090	2.3	3.23	20.9	0.94	23.9
F-225-62	2.25	57	2.06	52	0.62	16	.020	0.43	.095	2.4	3.65	23.5	0.26	6.6
F-225-94	2.25	57	2.06	52	0.94	24	.017	0.43	.095	2.4	3.65	23.5	0.56	14.2
F-225-137	2.25	57	2.06	52	1.37	35	.017	0.43	.095	2.4	3.65	23.5	0.99	25.1
F-250-142	2.50	64	2.31	59	1.42	36	.017	0.43	.095	2.4	4.54	29.3	1.04	26.4
F-250-150	2.50	64	2.31	59	1.50	38	.017	0.43	.095	2.4	4.54	29.3	1.12	28.4
F-250-153	2.50	64	2.00	51	1.53	39	0.18	0.46	.250	6.4	3.97	25.6	1.10	27.9
F-275-112	2.75	70	2.44	62	1.12	28	.024	0.61	.155	3.9	6.62	34.1	0.57	14.5
F-300-119	3.00	76	2.69	68	1.19	30	.030	0.76	.155	3.9	6.35	41.0	0.64	16.3
F-319-100	3.19	81	2.88	73	1.00	25	.024	0.61	.155	3.9	8.78	46.7	0.45	11.4
F-325-131	3.25	83	2.94	75	1.31	33	.024	0.61	.155	3.9	7.52	48.5	0.76	19.3
F-328-148	3.28	83	2.75	70	1.48	38	.017	0.43	.265	6.7	7.14	46	0.76	19.3
F-350-212	3.50	89	3.18	81	2.12	54	.030	0.76	.160	4.1	8.76	56.5	1.72	43.7
F-375-132	3.75	95	3.44	87	1.32	34	.022	0.56	.155	3.9	10.15	65.5	0.77	19.6
F-375-225	3.75	95	3.44	87	2.25	57	.024	0.61	.155	3.9	10.15	65.5	1.70	43.2
F-400-400	4.00	102	3.69	94	4.00	102	.024	0.61	.155	3.9	11.61	74.9	3.49	87.6
F-402-154	4.02	102	3.70	94	1.54	39	.032	0.81	.160	4.1	11.70	75.5	0.88	22.4
F-450-275	4.50	114	4.00	102	2.75	70	.035	0.89	.250	6.4	14.18	91.5	1.97	50.0
F-460-450	4.60	117	4.00	102	4.50	114	.040	1.02	.300	7.6	14.51	93.6	3.6	91.4
F-475-82	4.75	121	4.37	111	0.82	21	.035	0.89	.190	4.8	16.32	105.3	0.10	2.5
F-475-187	4.75	121	4.27	108	1.87	47	.035	0.89	.240	6.1	15.97	103.0	1.09	27.7
F-475-187	4.75	121	4.25	108	1.87	47	.035	0.89	.250	6.4	19.63	102.6	1.09	27.7
F-500-300	5.00	127	4.50	114	3.00	76	.035	0.89	.250	6.4	17.71	114.3	2.22	56.4
F-531-256	5.31	135	4.13	105	2.56	65	.039	0.99	.590	15	17.49	112.8	1.35	34.3
F-550-175	5.50	140	5.00	127	1.75	44	.035	0.89	.250	6.3	21.64	139.6	0.97	24.6
F-550-337	5.50	140	5.00	127	3.37	86	.035	0.89	.250	6.3	21.64	139.6	2.59	65.8
F-600-513	6.00	152	5.50	140	5.13	130	.040	1.02	.250	6.3	30.66	167.4	4.35	110.5
F-675-232	6.75	171	6.25	159	2.32	59	.035	0.89	.250	6.3	33.17	214.03	1.54	39.1
F-750-150	7.50	191	7.00	178	1.50	38	.035	0.89	.250	6.4	41.26	266.2	0.72	18.3
F-800-400	8.00	203	7.50	191	4.00	102	.035	0.89	.250	6.3	47.15	304.2	3.22	81.8
F-1000-200	10.00	254	9.25	235	2.00	51	.050	1.27	.375	9.5	72.72	469.2	1.02	25.9
F-1000-225	10.00	254	9.50	241	2.25	57	.035	0.89	.250	6.4	74.62	481.4	1.47	37.3
F-1000-412	10.00	254	9.50	241	4.12	105	.035	0.89	.250	6.4	74.62	481.4	3.34	84.8
F-1000-412	10.00	254	9.50	241	4.12	105	.040	1.02	.250	6.4	82.47	481.4	3.34	84.8
F-1188-538	11.88	302	11.38	289	5.38	137	.040	1.02	.250	6.3	106.18	685.0	4.60	116.8
*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 diaphragm seals.