The high impact force generated by the Allied Hy-Ram is produced mainly from two sources - compressed nitrogen gas "pre-charge" and hydraulic oil pressure. The Hy-Ram’s impact frequency, commonly referred to as "blows per minute" (BPM), is proportional to the amount of oil flowing through the Hy-Ram.
Unquestionably, "pre-charge", oil pressure, and oil flow are all significant elements of optimum Hy-Ram productiveness and should be checked following any complaint from the machine operator that reports unsatisfactory performance. Refer to Hy-Ram Nitrogen Pre-Charge Settings for proper "precharge" pressures, filling and testing procedure. Conversely, any Hy-Ram working beyond its maximum oil flow and pressure parameter is in jeopardy of reduced component life and reliability. To maximize optimum performance, a copy of the Hy-Ram Oil Flow and Pressure Specifications table of current production models has been provided. You will note the specification figures provide a minimum to maximum range. Naturally, optimum Hy-Ram productiveness is achieved at the maximum recommended range, but all Hy-Rams can maintain satisfactory production if required to operate at the lesser pressure and flow settings of that range.
Refer to S.I.L. HK 99-01 for instructions on adjusting flow & pressure.
| Hy-Ram Oil Flow and Pressure Settings |
Hy-Ram
Model |
Hydraulic
Oil Flow
(Min GPM) |
Impact
Frequency
(Min BPM) |
Hydraulic
Oil Flow
(Max GPM) |
Impact
Frequency
(Max BPM) |
Operating
Pressure
(Min PSI) |
Operating
Pressure
(Max PSI) |
| 700B |
4 |
700 |
9 |
1500 |
1300 |
1750 |
| 711B |
7 |
450 |
12 |
1150 |
1300 |
1900 |
715B
s/n 463- |
9 |
400 |
15 |
1150 |
2000 |
2600 |
715B
s/n 463+ |
9 |
400 |
15 |
1150 |
1750 |
2000 |
| 725B |
13 |
450 |
24 |
1200 |
1300 |
1900 |
| 730 |
12 |
400 |
22 |
1150 |
1600 |
2000 |
| 735CS |
16 |
600 |
26 |
1000 |
1600 |
2300 |
| 740 / 740CS |
18 |
350 |
32 |
800 |
1750 |
2450 |
| 745 / 745CS |
18 |
350 |
32 |
800 |
1750 |
2600 |
| 750CS |
24 |
*350 / 700 |
32 |
*600 / 1200 |
2000 |
2450 |
| 755CS, 755B |
27 |
**350 |
37 |
**680 |
2200 |
2600 |
| 770CS |
34 |
*360 / 720 |
45 |
*480 / 960 |
1750 |
2000 |
| 775CS, 775B |
34 |
**360 |
42 |
**600 |
2300 |
2600 |
| 785CS, 785B |
37 |
**280 |
48 |
**550 |
2300 |
2600 |
| 795CS |
53 |
**250 |
71 |
**550 |
2300 |
2600 |
| 797CS, 797B |
64 |
**320 |
79 |
**600 |
2300 |
2600 |
| 805CS, 805B |
66 |
**240 |
85 |
**530 |
2300 |
2600 |
| 905CS |
105 |
**330 |
121 |
**470 |
2300 |
2750 |
| 905B |
95 |
**280 |
119 |
**450 |
2300 |
2600 |
For maximum Hy-Ram performance, return pressure should not exceed 175 psi.
Circuit relief valve should begin to open (crack) at the Operating Pressure Maximum value.
Maximum, full open relief setting should not exceed 3000 psi.
* Model includes a dual frequency feature, selected by the operator.
** Model includes the AutoControl. feature that automatically adjusts frequency. (low range shown)
