DIAPHRAGM CLASSES
CLASS 4C
The Class 4C is similar to the Class 4 except that the convolution is molded in. The suggestions, pressures and other information, with regard to flange retention, listed under the “Description” of Class 4 (see page 7 of design manual) also apply to the Class 4C.
Because it is molded in the “as-installed” configuration, the Class 4C diaphragm need not be inverted at installation. The pre-convoluted design has a small spring gradient or centering effect, which tends to return the diaphragm to its “as-molded” or neutral plane position. The design can be fastened to the piston with a flat retainer plate.
The stroke of these diaphragms is limited since deep-molded convolutions are impractical to manufacture and are better suited for limited strike lengths.
| DC | .25 to .99 | 1.00 to 2.50 | 2.51 to 4.00 | 4.01 to 8.00 | 8.01 and up |
| H | (As required to yield design stroke (See standard size tables and Note 2 below. | ||||
| DC | Tolerances on DC and DP are ± .010" per inch of diameter but the tolerance will be no less than ±.010" or greater than ±.060" | ||||
| Dp | |||||
| WH & WF | .020 ± .003 | .020 ± .004 | .030 ± .004 | .035 ± .005 | .045 ± .007 |
| WSW | .015 ± .003 (Code “B”) | .017 ± .003 (Code “C”) |
.024 ± .004 (Code “D”) |
.035 ± .005 (Code “F”) |
.045 ± .007 (Code “H”) |
| F | 1/32 R. | 1/16 R. | 3/32 R. | 1/8 R. | 1/8 R. |
| DF | DC + 3/4" See Note 3 |
DC + 1" See Note 3 |
DC + 1-1⁄2" See Note 3 |
DC + 2" See Note 3 |
DC + 2" See Note 3 |
NOTES:
1. Standards are supplied with a button on the pressure side. 1/8" diameter x 3/32" high on bore sizes 1" and over.
2. Height tolerance is ± .015
3. Trim tolerances
Hole Diameter OD Trim
Diameter Tolerances
0 - 1.00" ±.010"
1.01 - 3.01" ±.015"
over 3.01" ±.020"
4. Dimensions and tolerances pertain to Bellofram Rolling Diaphragms as manufactured and not to dimensions and tolerances of mating parts.