munirabbasi Posted December 30, 2020 Share Posted December 30, 2020 Hello T56A -15 power plant Pneumatic Expertise T56A-15 (C-130 E model) engine can provide approximately 155 pounds of air flow per minute at 635F and 125 pounds per square inch of gauge pressure. Bleed manifold pressure gauge is mounted in F/deck (direct gauge) display approximately 70 PSIG .where remaining pressure of the engine flow? Best Regards Munir Abbasi Home of Hercules Pakistan Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted December 31, 2020 Share Posted December 31, 2020 at sea level, a 0/low time compressor will make 80 to 85psi at normal ground idle. This increases as throttle is advanced towards take off an TIT increases. The highest I have ever seen was 130psi. This was a 0 time engine where the CDP fell in "high" zone of the compressor graph. Compressor performance is based on OAT and pressure altitude. Quote Link to comment Share on other sites More sharing options...
munirabbasi Posted December 31, 2020 Author Share Posted December 31, 2020 10 hours ago, pjvr99 said: at sea level, a 0/low time compressor will make 80 to 85psi at normal ground idle. This increases as throttle is advanced towards take off an TIT increases. The highest I have ever seen was 130psi. This was a 0 time engine where the CDP fell in "high" zone of the compressor graph. Compressor performance is based on OAT and pressure altitude. Thanks for excellent response .let me rephrase my query regarding Engine bleed output pressure at Engines throttle higher setting. normally the pressure is indicated in flight deck bleed manifold Gage approximately 70 to 80 PSIG where one engine output pressure is 125 PSIG at 155 ppm . Question arise in my mind that one engine bleed output is metered 125psig but all four engines operating at higher throttles setting is droped to 70 to 80 psig when both air -conditioning are ruing condition with flow rate of 70 ppm and 30 ppm. Best regards Munir Abbasi Home of Hercules Pakistan Quote Link to comment Share on other sites More sharing options...
hehe Posted December 31, 2020 Share Posted December 31, 2020 The Ejected pressure from the engine should never indicate exactly in the flight deck for quite a few reasons. 1. Pressure drops across distance. In order to get 125 psi in the flight deck, the engine would need to be making 150-ish psi at the engine (just an estimate). Pressure drops across distance because flow and volume is required to get that pressure across a distance. 2. The system has allowable and normal leaks. Every valve in the system is bleeding off or leaking a small amount. Some are calibrated to leak a certain amount and others just leak as a result of their design. Very few pneumatic systems are perfectly leak proof. For example, if you have 20 valves in a system and they are all leaking small amounts of air, your 125 psi becomes more like 70 after the bleed offs. This is why the system has a bleed down time. The drop from 30 to 15 psi in 22 seconds or more is a indication a satisfactory level of "normal" leakage. If there were no leaks in the system at all, your bleed air pressure would never drop. 3. Almost all systems are like this. Hydraulics, fuel, electrical, oxygen, etc. The system is designed to provide a higher amount than is required so that it can "bleed off" some for normal system losses and still provide a set amount. Hope that helps. Quote Link to comment Share on other sites More sharing options...
munirabbasi Posted January 1, 2021 Author Share Posted January 1, 2021 7 hours ago, hehe said: The Ejected pressure from the engine should never indicate exactly in the flight deck for quite a few reasons. 1. Pressure drops across distance. In order to get 125 psi in the flight deck, the engine would need to be making 150-ish psi at the engine (just an estimate). Pressure drops across distance because flow and volume is required to get that pressure across a distance. 2. The system has allowable and normal leaks. Every valve in the system is bleeding off or leaking a small amount. Some are calibrated to leak a certain amount and others just leak as a result of their design. Very few pneumatic systems are perfectly leak proof. For example, if you have 20 valves in a system and they are all leaking small amounts of air, your 125 psi becomes more like 70 after the bleed offs. This is why the system has a bleed down time. The drop from 30 to 15 psi in 22 seconds or more is a indication a satisfactory level of "normal" leakage. If there were no leaks in the system at all, your bleed air pressure would never drop. 3. Almost all systems are like this. Hydraulics, fuel, electrical, oxygen, etc. The system is designed to provide a higher amount than is required so that it can "bleed off" some for normal system losses and still provide a set amount. Hope that helps. Tanks Munir Abbasi Home of Hercules Pakistan Quote Link to comment Share on other sites More sharing options...
AMPTestFE Posted January 16, 2021 Share Posted January 16, 2021 And remember, on those older E models, you have the two urinal drain bleeds, in addition to the jet pump on the outflow valve and the safety valve constant flow points. Quote Link to comment Share on other sites More sharing options...
NATOPS1 Posted January 29, 2021 Share Posted January 29, 2021 ALSO FYI; The flight station mounted bleed air gauge reads 6 PSI lower than actual pressure. Add 6 to the indicated pressure for actual pressure being supplied. Quote Link to comment Share on other sites More sharing options...
munirabbasi Posted February 10, 2021 Author Share Posted February 10, 2021 On 1/17/2021 at 4:11 AM, AMPTestFE said: And remember, on those older E models, you have the two urinal drain bleeds, in addition to the jet pump on the outflow valve and the safety valve constant flow points. Thanks Munir Abbasi Quote Link to comment Share on other sites More sharing options...
munirabbasi Posted February 10, 2021 Author Share Posted February 10, 2021 On 1/30/2021 at 12:30 AM, NATOPS1 said: ALSO FYI; The flight station mounted bleed air gauge reads 6 PSI lower than actual pressure. Add 6 to the indicated pressure for actual pressure being supplied. Thanks Munir Abbasi Quote Link to comment Share on other sites More sharing options...
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