No. I remember an item attached to the pressure line off the EDP on 762 engines, with JT9-7R4's. About 5" dia x 4" that I believe was supposed to dampen surges from the pump. Don't remember it on the 763's though, but it's been a few years. This sounds like a similar item.
PhilSquares From , joined Dec 1969, posts, RR: Reply 5, posted (7 years 4 months 2 days 12 hours ago) and read 4742 times:
Quoting Sfomb67 (Reply 4): No. I remember an item attached to the pressure line off the EDP on 762 engines, with JT9-7R4's. About 5" dia x 4" that I believe was supposed to dampen surges from the pump. Don't remember it on the 763's though, but it's been a few years. This sounds like a similar item.
Sounds like the description of a hydraulic accumulator.
Dougloid From , joined Dec 1969, posts, RR: Reply 8, posted (7 years 4 months 2 days 8 hours ago) and read 4716 times:
Quoting Charliecossie (Reply 7): Known as a "ripple damper".
Additional to the accumulator.
Doesn't have to be mounted at the pump.
Or a "snubber". Ever have a water hammer in your residential supply? Same thing in hydraulic systems unless you install a snubber. An accumulator which is permanently connected does the same thing but there are systems that don't utilize an accumulator.
Okie From United States of America, joined Jul 2003, 2346 posts, RR: 3 Reply 9, posted (7 years 4 months 2 days 6 hours ago) and read 4710 times:
Pulsation Damper would be the correct term. Generally used in high pressure pump applications to decrease vibrations induced into the system, hydraulic in this case, generated by the pump as each piston/vane/gearoter discharges into the high pressure side of the system and causes vibration.
While somewhat similar to an accumulator the devices are pretty much "tuned" for lack of a better word for the frequency/quantity of fluid discharged by each piston/vane/gearoter displacement and pressure of the system. They do not store pressurized fluid like an accumulator for later or short term demands that exceed the pump capacity.
A friend of mines dad was in that business for years and built Pulsation Dampers for all types of hydraulic and pump applications from small 3 gpm hydraulic pumps that would fit in the palm of your hand to some mongo units used in oil field pumps for offshore production that were 36" in diameter and 10 feet long.
Okie From United States of America, joined Jul 2003, 2346 posts, RR: 3 Reply 12, posted (7 years 4 months 2 days 3 hours ago) and read 4678 times:
Quoting Sfomb67 (Reply 11): pulsation damper is the same thing as a pressure resonance suppressor ?
I would say close enough Sfomb67
I am not familiar with aircraft pump speeds and designs but a typical industrial application using a standard NEMA 1750 rpm motor and a 9 piston pump you are looking at 15,750 pulses/min or 262.5 pulses/sec. for frequency. Pressure, frequency, line size and volume of piston/vane displacement is calculated for a proper fit of a pulsation damper. Most designs I have seen are mounted directly to the pump or within a very short distance of the pump. The two most popular designs I have seen were "inline" similar to what Troubleshooter linked or a "right angle" design that mount directly to the pump discharge. The design that HAWK21M has a picture of I have only seen in "system" pulsation damping where you are dampening very low frequency applications, opening and closing of valves in the hydraulic system although they would probably work to some degree for pump dampening.