Air Venturi or Hatsan Compressor Question

[jking]

Looking for some answers from you AV/Hatsan owners since these units are basically the same. I'm trouble shooting an issue and I have a couple of questions. One, when your compressor is running can you feel a definite flow of air coming out of the oil fill vent hole?

Question two, is your first stage getting hot (too hot to keep your hand on) while it running even for a short time, 10-15mins.

I'm thinking the seals on the second stage piston might be leaking compressed air back into the crankcase to explain the blow of air from the vent hole and as for the hot first stage maybe the check valve on it is letting second stage heated air back into that side.

It'll compress to 4500 with the hose deadheaded but it does take longer than what I think it should.

Thanks in advance

Jimmy

 

[2fast2furious]

Crack case will have air blowing out from it cause the lower pressure have a piston that push air up and into the high cylinder side. But when it push down it is also pushing air into the crack case. That is why it had a breather. Try plugging the breather and it will eventually build up enough pressure and blow the crack case. That's why you use the breather. Also normal to see small white smoke coming from the breather vent hole. Why would you even put your hands on the cylinder head. Of course its gonna be burning hot and will burn your hands. Never place your hands on the cylinders or stainless tubing..they are burning hot reaching over 130 to 160+ degree. On my lighting it takes 20 mins to fill from 3000 psi to 4500 psi on a 74cf tank. I believe that is average time for these compressor. If it's taking way longer, check for leaks. Even the smallest leak that you wont hear will make fill time way longer.

 

[jking]

That's right at the same fill time for my 74cuft tank, was anyway. Maybe I just never noticed the constant flow of air coming out of the breather since normally the cover is on it. I checked the FS cylinder temp with temp gun and it was running 180-190, that's down on the cylinder and not the head. The head was cooler. At the same time the SS cylinder again down on the cylinder in between the fins was running about 120. The coolant was running about 116 degrees. It would still pressure up the the hose dead headed (small volume) but I couldn't see much movement at all while hooked up to one of my SCBA's setting at 3100#. Also cleaned the FS check housing and installed a new spring and check. That didn't make any difference. I do believe the SS stage rings have gone south. I've changed them before which is really easy.

jk

 

[airgunfans]

I don't have the compressor but I believe there should not be a "constant flow of air coming out of the breather". When the piston goes down, the air inside the crankcase is compressed so yes, the air will come out. However, when the piston goes up, air will be sucked back into the crankcase via the same breather so on average, there should not be any net outflow. I tend to agree with your suspicion that there is a leakage of compressed air back into the crankcase.

 

[jking]

Thanks airgunfans, the only difference might be that it's compressed on the way out with velocity behind it and as fast as the pistons cycle then maybe it feels like a constant blow, just a thought. I have some of the high pressure seals ordered anyway so we will see. In the mean time I'm still looking at different components for any clues. It's always a learning process so I don't mind.

jk

 

[jking]

Found the main problem, kind of as expected. The high pressure seals were shot. I order some from AV but also order quite a few more from china. Looks like a routine change at least every six months or until the performance starts falling off would be a good idea.

I also dug into the HP head and inspected the two valves a little closer. Found them pretty dirty with some build up on them. They cleaned up nicely with some 1200grit sand paper.

 

[bandg]

Interesting. HP piston and rings looks VERY similar to Yong Heng piston. I've always been hesitant to clean the valve surface with anything abrasive thinking the scratches might allow leaking. I've only cleaned such with brake cleaner. Hope you get it working well.

 

[airgunfans]

I share the same impression. If I was just shown the pictures, I would also have said the parts are from Yong Heng

 

[airgunfans]

I've always been hesitant to clean the valve surface with anything abrasive thinking the scratches might allow leaking. I've only cleaned such with brake cleaner. Hope you get it working well.

For my Yong Heng, I clean those reed valve blades with metal polishing paste like Brasso. The carbon build up there cannot be removed by solvent. There has been reports that those carbon build up has caused pressure build up failure because the valve cannot close up completely. 

 

[airgunfans]

I have just checked my Yong Heng . There is indeed a constant outflow of air from the breather hole when the compressor is running. The airflow can be easily felt by my fingers. The compressor is working normally as evident by the fact that it is filling up the big gold filter as quickly as it did when it was new - from empty to 4500 psi in 104 seconds. There is not any visible oil mist in the airflow though. I therefore believe the phenomenon observed by the OP is normal. 

 

[jking]

Thanks for checking airgunfans. Once I get my seals replaced I'll check it again. Be a good opportunity for a comparison. Your fill time for the big gold filter and the hose was really good. Mine is nothing like that currently but I'll have an update later after the repairs. 

jk

 

[bandg]

I've always been hesitant to clean the valve surface with anything abrasive thinking the scratches might allow leaking. I've only cleaned such with brake cleaner. Hope you get it working well.

For my Yong Heng, I clean those reed valve blades with metal polishing paste like Brasso. The carbon build up there cannot be removed by solvent. There has been reports that those carbon build up has caused pressure build up failure because the valve cannot close up completely.

I must be cleaning mine too often. I've never seen hard carbon deposits on it that wouldn't wipe off with a towel and brake cleaner. Brasso is a good idea if such is needed and I guess Flitz might work as well along with some type of chrome polish. Fine sandpaper might not cause a problem but it was something I felt I'd avoid.

 

[jking]

I've never pulled the seat or what ever it's called to find the large valve. The unit will be 3 years old in December so they've never been touched. Now that I know a whole lot more about the design I'll be doing more routine maintenance on it before they get in that shape again. I'd think about every 6-9 months would be a lot better that what it's been getting and the parts might clean up a little easier. I tried steel wool to start out with but that didn't cut it. I'd check the high pressure piston seals at the same time.

jk

 

[jking]

Update.... I just received my new piston seals from Pyramid Air today. I hustled home and commenced installing a set of three. Since these are one piece and a continuous ring they have to be stretched to fit over the piston and into the grooves. AV makes a kit to install the seals which consist of a cone to stretch the new seals and a cylinder to size them before you slide the cylinder head over the end of the piston.

After getting them in place I reshaped them into the grooves and finished that off with the included nylon sizing cylinder. I then re-installed the cylinder head and all associated pieces and got it started up. It ran great, sounded good and compressed my system pretty quick to 4500#. Upon inspecting hoses and connections with soapy water I did find a hole in a hose and a fitting leaking in the body and not the threads. This hose feeds pressure to the onboard gauge and auto shut down switch. Pyramid air sales them but are out of stock at the time.

Dang it, always something. I'll get this fixed and it should be good to go. 

jking

 

[rgordonwv]

Hey guys,

I’m so glad I found this forum string. I have a Hatsan Lightning Compressor that has quit working. It pumps up to about 1100 psi, then stops rising and holds there. I have check and rechecked for air leaks and have found none not the air supply side (outside hpa lines and fittings). I assume something is leaking on the inside, it may be the piston seals. I’ve tried for a week to get some answers from Hatsan. They did finally respond and say there could be a piston seal bad. However, they gave no indication if they have the parts, or even a schematic/parts list. I had to start a new request for that information and still haven’t heard back. My first question is will the AV seals fit the Hatsan compressor? Does PyramydAir sell the valve seals with the tool for installation or do you get that from AV? Finally, while trying to find leaks, I noticed a lot of pressure coming from the coolant reservoir lid (a pin hole vent). I never noticed it before and thought it may be an indicator of an internal leak. It only happens while the compressor is running.

Thanks for all of the good info and pictures. I hope to get my compressor running soon. Right in the middle of hunting season!

 

[jking]

I'm not sure if the AV seals will work in the Hatsan. I'd think there would be a good chance that they will. Pyramid Air does sell the installation kit and seals. The AV uses only three but your Hatsan might take four. It's very easy to remove the second stage cylinder and take a look at the high pressure piston seals. PM me if I can help in any way.

JK

 

[airgunfans]

How long did it take for those plastic seals to shrink back to the original size after being stretched by such an apparently big extent ? 

 

[jking]

It would probably take a long time on its own if even then it would. I warmed them up with a hair drier and shaped them by rolling them between my fingers and then ran the nylon shaper over them for the final sizing.

jk

 

[bandg]

Update.... I just received my new piston seals from Pyramid Air today. I hustled home and commenced installing a set of three. Since these are one piece and a continuous ring they have to be stretched to fit over the piston and into the grooves. AV makes a kit to install the seals which consist of a cone to stretch the new seals and a cylinder to size them before you slide the cylinder head over the end of the piston.

After getting them in place I reshaped them into the grooves and finished that off with the included nylon sizing cylinder. I then re-installed the cylinder head and all associated pieces and got it started up. It ran great, sounded good and compressed my system pretty quick to 4500#. Upon inspecting hoses and connections with soapy water I did find a hole in a hose and a fitting leaking in the body and not the threads. This hose feeds pressure to the onboard gauge and auto shut down switch. Pyramid air sales them but are out of stock at the time.

Dang it, always something. I'll get this fixed and it should be good to go. 

jking

Nice pictures and good information. I would consider cutting the nylon tool off on the tapered end to the point that it matches piston diameter. Then you could slide the ring on the end of the tool and onto the high pressure piston with less stretching. It doesn't seem there is any reason to need to push the ring all the way over the widest part of the tool. Might not make any operational difference but the amount of stretching shown on the rings seems extreme.

 

[jking]

Good point bandg, a little less stress on the rings might go a long way. The tool is hollowed out on the bottom to assist in holding it in place on top of the piston but again, probably not necessary. Next time and I'm sure there will be one, I'll just stretch it enough to get it on the piston, maybe scribe a mark on the cone. Thanks for the input.

jk