A Couple of Fuel Day-Tank Questions

[BlueStringPudding]

QUESTION ONE: Has anyone ever used a heater's day tank like this one [first photo - ignore the horizontal pole above the tank, it's not part of the set up]. The tank has a hand pump mechanism built in to the top to add slight pressure. 

When I pull the pump doohickey up and down it doesn't feel snug, there's a slight wobble and I don't feel any pressure or resistance.  I think that's why I can't introduce any pressure to the tank. I'm not convinced that the various parts that are screwed on / slid onto the pump's spindle are necessarily in the right order - It's been dismantled and rebuilt a few times to try different combinations of parts and neither of the combination improve it.  I've taken photos of two different combinations of the pump parts that I've tried (plus I later added a white plastic washer i happened to have lying around in case that would help create a vacuum but it doesn't). [Second and third photos] What should the insides of the pump look like? At the moment it's got a tiny nut at the bottom, a metal ring I can't detach, a screw thread, a brass split ring which fits the screw thread and a cup shaped thing which looks like it's made of some sort of fibrous felt or suede-like material. I've no way of knowing if something is missing or in the wrong position. Any advice would be very welcome. 

 

QUESTION TWO:

Separate from the pump is a screw cap with comedy ears which has a cute little pressure gauge built into it. [Fourth photo]  It's got a twisty stalk thing on one side which allows its own cap to slide up and down a few millimetres, exposing more or less of a breather hole to the tank depending on how low the twister is turned down. How should this be set / twisted and for what scenarios? 

 

Thanks.

[bizzard]

4 minutes ago, BlueStringPudding said:

QUESTION ONE: Has anyone ever used a heater's day tank like this one [first photo - ignore the horizontal pole above the tank, it's not part of the set up]. The tank has a hand pump mechanism built in to the top to add slight pressure. 

When I pull the pump doohickey up and down it doesn't feel snug, there's a slight wobble and I don't feel any pressure or resistance.  I think that's why I can't introduce any pressure to the tank. I'm not convinced that the various parts that are screwed on / slid onto the pump's spindle are necessarily in the right order - It's been dismantled and rebuilt a few times to try different combinations of parts and neither of the combination improve it.  I've taken photos of two different combinations of the pump parts that I've tried (plus I later added a white plastic washer i happened to have lying around in case that would help create a vacuum but it doesn't). [Second and third photos] What should the insides of the pump look like? At the moment it's got a tiny nut at the bottom, a metal ring I can't detach, a screw thread, a brass split ring which fits the screw thread and a cup shaped thing which looks like it's made of some sort of fibrous felt or suede-like material. I've no way of knowing if something is missing or in the wrong position. Any advice would be very welcome. 

 

QUESTION TWO:

Separate from the pump is a screw cap with comedy ears which has a cute little pressure gauge built into it. [Fourth photo]  It's got a twisty stalk thing on one side which allows its own cap to slide up and down a few millimetres, exposing more or less of a breather hole to the tank depending on how low the twister is turned down. How should this be set / twisted and for what scenarios? 

 

Thanks.

Is there increasing pressure as you pump the pump knob, pressure on the down stroke. To hold the pressure in the tank there should be a one way ball valve at the pumps base, Perhaps the ball is not seating on the up stroke and keeps letting the pressure escape. Its all like a Tilley pressure lamp.

[bizzard]

I think the little knurled knob thing next to the filler maybe for pressure release when shutting the heater down. Tilley lamps and paraffin blowlamps have similar.

[David Mack]

1. There should be fixed washers above and below the soft cup thing (open end downwards) clamping it to the shaft, so that when you push the handle down the cup is forced down. If it just slides on the rod it's doing nothing.

2. If it's a vent, then you can't pressurise the tank!

 

[Tony Brooks]

2, well you could if the vent is screwed down and it seals.

 

I think the order of assembly onto the shaft is as in photo 3 except the white (nylon?) washer should be immediately on top of what looks like a leather seal. I also think you may do well to soak the leather in light oil overnight and then push its lips outwards before putting it all back together.

 

If it is supposed to build up significant pressure then it needs a foot valve in the bottom of the pump body. look down the hole to see if it has one and if anything is jambing it open.

Edited November 27, 2018 by Tony Brooks

[BlueStringPudding]

54 minutes ago, bizzard said:

Is there increasing pressure as you pump the pump knob, pressure on the down stroke. To hold the pressure in the tank there should be a one way ball valve at the pumps base, Perhaps the ball is not seating on the up stroke and keeps letting the pressure escape. Its all like a Tilley pressure lamp.

No discernable pressure or resistance at all. I've never used a Tilley lamp so have nothing to compare it to unfortunately. Thanks for the advice, though.

16 minutes ago, Tony Brooks said:

2, well you could if the vent is screwed down and it seals.

 

I think the order of assembly onto the shaft is as in photo 3 except the white (nylon?) washer should be immediately on top of what looks like a leather seal. I also think you may do well to soak the leather in light oil overnight and then push its lips outwards before putting it all back together.

Okay. Thanks. The white washer isn't necessarily originally from the tank. It's just something I had lurking in my toolbox so I thought I'd try it.  I'll soak the leather (well, suede) cup thing tonight and see what happens.  I've got a choice of olive oil or diesel! Will either of those do to soak it with? Thanks. 

 

 

By the way, what's a foot valve? I can't actually see down into tube that the pump sits in. The opening is very narrow and I can't dislodge what appears to be a large nut where the base of the pump tube meets the tank, making me suspect it's integral to the tank and doesn't necessarily unscrew

Edited November 27, 2018 by BlueStringPudding

[bizzard]

1 hour ago, BlueStringPudding said:

No discernable pressure or resistance at all. I've never used a Tilley lamp so have nothing to compare it to unfortunately. Thanks for the advice, though.

Okay. Thanks. The white washer isn't necessarily originally from the tank. It's just something I had lurking in my toolbox so I thought I'd try it.  I'll soak the leather (well, suede) cup thing tonight and see what happens.  I've got a choice of olive oil or diesel! Will either of those do to soak it with? Thanks. 

 

 

By the way, what's a foot valve? I can't actually see down into tube that the pump sits in. The opening is very narrow and I can't dislodge what appears to be a large nut where the base of the pump tube meets the tank, making me suspect it's integral to the tank and doesn't necessarily unscrew

The foot valve will be a ball bearing that is pushed down off its seat when you push the pump handle down to pump pressure into the tank. On the up stroke of the pump handle the ball is pushed up onto its seat by the pressure pumped into the tank to stop the pressure in the tank escaping.

[Jen-in-Wellies]

I suspect that the pump comes from a pressure lamp, or stove and has been added to the tank. If you can't get it to pressurise, then this company may be a possible source of spares.

https://fettlebox.co.uk/index.php

The hard bit is going to be identifying what the pump is from.

 

Jen

[BlueStringPudding]

Thanks. I've managed to take some photos down the pump tube with the spindle/plunger removed. I've no idea what it is I'm looking at down at the bottom there but maybe you guys do? The valve? Does it look like it should do? ? ?

 

 

[springy]

Sometimes that sort of pump requires quite vigorous operation to gain enough pressure to properly splay the washer and form a seal. 

 

springy

[bizzard]

The ball bearing can just be seen, shining on the other side of that little hole in the middle.

[BlueStringPudding]

7 minutes ago, springy said:

Sometimes that sort of pump requires quite vigorous operation to gain enough pressure to properly splay the washer and form a seal. 

 

springy

Thanks. By "washer" do you mean the suede cup thing? It's not very splayed at the moment. It doesn't seem to fill the space in the tube which I'm guessing it's supposed to. 

 

Should there be some sort of rubber washer or seal at the very top of the pump spindle, near the handle end? At the moment it looks like it's just brass on brass.

[BlueStringPudding]

16 minutes ago, bizzard said:

The ball bearing can just be seen, shining on the other side of that little hole in the middle.

 

Yay! Me ball's intact! ?

[springy]

Yes the leather cup washer - very like the one in a bicycle pump, as has been said, starting from the retaining nut, next a smaller solid (brass) washer inside the cup, then the cup washer itself and finally there should be a larger washer behind the cup, smaller than the OD of the cup but only slightly. The cap nut should not have a seal as that is where air is drawn into the pump body on the up stroke, passing by the cup, to then splay the cup and be forced through the foot valve into the tank.

 

springy

[BlueStringPudding]

Ah. That makes sense. Thanks. At the moment the cup is totally stiff with vertical sides. It was very hard to position it as in photo 3 because it didn't want to let the small washer in. Hopefully soaking it will soften it up enough to make it splay out when it needs to. I'm soaking it in diesel at the moment. Hope that proves to be the right thing to do to give it some squidge.

[Tony Brooks]

I think I might be able to see something like a blade of old grass coming up the side of the ball and partially across the top. Whatever it is, unless its just light or a stain, I think it may well stop the ball sealing.

[billh]

I don't think the sight "glass" on the end of the tank is BSS compliant if it's a plastic tube or even if it was glass. Sorry to sound depressing?

[Tacet]

The leather pump washer should not travel all the way up and down the pump shaft, of course.  But it should waggle up and down a few mm between the nut (on the end) and a washer behind, which sits on a shoulder on the shaft.  This allows the air (that is to be compressed) to pass through the hole in thee pump washer.  If its not as it should be, the air struggles to get drawn around the leather washer - and the pump knob tends to ping back down.

 

Bizzard and others may be right concerning about the non return valve (at the foot of the cylinder) being a ball bearing - but a nitrile/viton pip in a carrier is more usual.  If so, you unscrew the carrier with either a screwdriver (which doesn't look to be the case from the pics) or by a cylindrical something with a slot in its end face that grips the flats.  But that is not the initial problem anywat.

 

 

Someone has used parts from a pressure lantern.  The gauge/manometer is probably from a Petromax - or one of its clones, although Optimus and others used something similar.   It's not British. I'm not  sure that  the pump came from the same place - but it doesn't really matter.

 

Oil and spread the pump leather, reassemble.  You should have firm resistance to the inward stroke but not the outward.

 

 

[BlueStringPudding]

50 minutes ago, Tacet said:

The leather pump washer should not travel all the way up and down the pump shaft, of course.  But it should waggle up and down a few mm between the nut (on the end) and a washer behind, which sits on a shoulder on the shaft.  This allows the air (that is to be compressed) to pass through the hole in thee pump washer.  If its not as it should be, the air struggles to get drawn around the leather washer - and the pump knob tends to ping back down.

 

 

There's definitely no pinging. Absolutely no pressure or resistance in the pull up or the push down. It slides in both directions totally unimpeded with barely any input from me. If I was to turn the tank upside down it would slide down and then if I turned the tank the right way up again the pump would slide quickly straight back down again at the speed of gravity. I haven't done that of course but I'm just trying to describe the total lack of any resistance. 

1 hour ago, Tony Brooks said:

I think I might be able to see something like a blade of old grass coming up the side of the ball and partially across the top. Whatever it is, unless its just light or a stain, I think it may well stop the ball sealing.

Not sure which bit that is. I suppose I could look for a stick to poke down there to see if there's something loose attached to it. 

[Tacet]

6 minutes ago, BlueStringPudding said:

There's definitely no pinging. Absolutely no pressure or resistance in the pull up or the push down. It slides in both directions totally unimpeded with barely any input from me. If I was to turn the tank upside down it would slide down and then if I turned the tank the right way up again the pump would slide quickly straight back down again at the speed of gravity. I haven't done that of course but I'm just trying to describe the total lack of any resistance. 

Not sure which bit that is. I suppose I could look for a stick to poke down there to see if there's something loose attached to it. 

Oil and spread the pump leather, reassemble.  You should have firm resistance to the inward stroke but not the outward

[WotEver]

56 minutes ago, Tacet said:

Oil and spread the pump leather, reassemble.  You should have firm resistance to the inward stroke but not the outward

Just like a bicycle pump (as has previously been said, I believe). 

[BlueStringPudding]

3 hours ago, WotEver said:

Just like a bicycle pump (as has previously been said, I believe). 

Ah, the ole assumption that at any point in my childhood I would have felt the need to dismantle a bicycle pump to see how it works. (I didn't) ?

[BlueStringPudding]

So the suede cap spent last night soaking in diesel and this afternoon was a different beast - much more pliable and able to splay the sides out. It fit snugly back in the tube and now the pump gives some resistance on the downward stroke but not the upward stroke. So that all sounds like it's working.

 

I was hoping the pressure gauge would give me an idea of how much, if any, pressure I was introducing into the tank. It's positioned way above my head so I've had to rather trickily take photos of the gauge while pumping the handle. As far as I can tell, the gauge ain't moving. However the drip feed to the heater hasn't stopped which it does do if the filler cap is tightly sealed and a vacuum forms above the head of fuel) and when I twiddle the little thing next to the filler cap gauge I hear it release some pressure with a slight hiss. So *I think* the pump is now working. Thanks for solving that part of the riddle for me! ?

 

The next part is how do I work out how many pumps to do and how frequently? At the moment the tank is about a third full of diesel and positioned 2.5ft above the Taylor's heater (drip feed). ideally the tank should be 4ft above the heater but there just isn't the ceiling height, and anyway I seem to remember reading that it should still work okay with just 2ft headroom. When the tank is not sealed, the drip rate gradually slows every 15 minutes ish, so I have to keep turning up the drip-rate dial up faster otherwise it eventually stops dripping and the flame goes out. I'd like to think that the pump will mean I won't have to keep doing that. But how many up-downs of the pump to do and how often? At the moment I've done 15, lifting the pump half its full height vigorous-stylee, for no reason other than I was trying to get a response from the pressure gauge. Since its ignoring me it's either kaput or I've not done enough pumpage.

The manual says to introduce 0.4psi per foot of lost head. So with my set up that should mean 0.4psi × 1.6 feet=0.64psi required using the manual pump.

Any ideas on numbers of pumps to do and how often please?

Thanks everyone. 

Edited November 28, 2018 by BlueStringPudding

[Tacet]

Not much pumping will be required to reach 0.64 psi.  It depends on how full the tank is (with fuel) as to how many strokes of the pump are required to raise the pressure by X psi.  If the tank is empty-ish, it will take more pumping to achieve a given pressure - but the pressure will decrease slower, and last longer before having to re-pump.

 

This type of pump was designed to allow you to reach about 30 psi/ 2 bar (somewhere near the redline) maximum using your thumb.  But at that pressure - your thumb will be hurting if you started from scratch.  The maximum pressure that can be acheived with a pump of this type (no matter how strong you are) is also a function of the swept and unswept volumes of the cylinder  

 

Does the manual say the maximum pressure/head that the heater will tolerate?  In theory, using the area of the pump tube you can work out how many lbs force (or Newtons) need to be applied:

 

Eg A pump tube of 16mm diameter (a reasonably common size) has an area of about 1/3 sq inches - so would require only 1/3lb to make 1 psi

Or 20 mm (also a reasonably common size) has an are of about 1/2 sq inches - so would require only 1/2 lb to make 1 psi

 

So in theory, when the calculated weight (lbs force) is no longer sufficient to make the pump travel - you have reached the relevant pressure.  But this ignores the pressure to lift the non-return valve off its seat and various types of friction.   

Edited November 28, 2018 by Tacet

[Tony Brooks]

36 minutes ago, BlueStringPudding said:

So the suede cap spent last night soaking in diesel and this afternoon was a different beast - much more pliable and able to splay the sides out. It fit snugly back in the tube and now the pump gives some resistance on the downward stroke but not the upward stroke. So that all sounds like it's working.

 

I was hoping the pressure gauge would give me an idea of how much, if any, pressure I was introducing into the tank. It's positioned way above my head so I've had to rather trickily take photos of the gauge while pumping the handle. As far as I can tell, the gauge ain't moving. However the drip feed to the heater hasn't stopped which it does do if the filler cap is tightly sealed and a vacuum forms above the head of fuel) and when I twiddle the little thing next to the filler cap gauge I hear it release some pressure with a slight hiss. So *I think* the pump is now working. Thanks for solving that part of the riddle for me! ?

 

The next part is how do I work out how many pumps to do and how frequently? At the moment the tank is about a third full of diesel and positioned 2.5ft above the Taylor's heater (drip feed). ideally the tank should be 4ft above the heater but there just isn't the ceiling height, and anyway I seem to remember reading that it should still work okay with just 2ft headroom. When the tank is not sealed, the drip rate gradually slows every 15 minutes ish, so I have to keep turning up the drip-rate dial up faster otherwise it eventually stops dripping and the flame goes out. I'd like to think that the pump will mean I won't have to keep doing that. But how many up-downs of the pump to do and how often? At the moment I've done 15, lifting the pump half its full height vigorous-stylee, for no reason other than I was trying to get a response from the pressure gauge. Since its ignoring me it's either kaput or I've not done enough pumpage.

The manual says to introduce 0.4psi per foot of lost head. So with my set up that should mean 0.4psi × 1.6 feet=0.64psi required using the manual pump.

Any ideas on numbers of pumps to do and how often please?

Thanks everyone. 

 

 

I don't  fully understand "lost head". I suspect it means that the heater requires a head of xxx - whatever the instructions say - and for every foot less than that it needs 0.64psi to push teh fuel into the heater. I would expect that at the specified head the fuel would gravity feed PROVIDING there was an air vent on the tank. This may be where the little screw thing comes in but it might just as well connect the tank to the gauge so try unscrewing the valve a few turns and then try pressurising the tank. IF the screw hisses its an air vent and if the gauge reads you know what it is for.

 

If you only partially fill the tank the extra air space will give you a longer period before the pressure drops.