Non return valve - Working principle?

[ravip]

The following pics are from a non return valve removed from a water geyser. Basically, I know that this device allows water to flow in only one direction. So, let me explain my confusion...

1. The arrow indicates the direction of flow - Pic 1 (Hence the threaded end should be the input)
2. Here is the inside of the threaded end - Pci2 (When the spring loaded plunger is pushed, this comes up and opens the valve)
3. Here is the inside of the opposite end - Pic3 (The output end) - On the outlet side is a spring loaded plunger which can be pressed in.

With the above configuration, I feel the arrow is inverted ????. I tried to figure it out, but failed!

 

[worgeordie]

The water should come IN the female side, never seen a non-return valve like 

that what's the other piece coming off it ?

regards Worgeordie

[wayned]

12 minutes ago, worgeordie said:

The water should come IN the female side, never seen a non-return valve like 

that what's the other piece coming off it ?

regards Worgeordie

I disagree, the water should come in the male Side, the direction of the arrow is correct.    The water pushes against the closed valve stopper and against the spring and the valve opens letting the water through.  If the water comes in the female end it will not go through as the pressure will keep the valve shut.  I have no idea what the "thingy" at a right angle is for.

[ravip]

Just now, worgeordie said:

The water should come IN the female side, never seen a non-return valve like 

that what's the other piece coming off it ?

regards Worgeordie

That's supposed to be a safety valve.

[ravip]

Just now, wayned said:

I disagree, the water should come in the male Side, the direction of the arrow is correct.    The water pushes against the closed valve stopper and against the spring and the valve opens letting the water through.  If the water comes in the female end it will not go through as the pressure will keep the valve shut.  I have no idea what the "thingy" at a right angle is for.

I too understood the same as you mention. What confuses me is that the plunger is on the female side (the white 'rod' in the middle. Pressure from the male side only 'seals' it more.

[Crossy]

The white rod is on the outlet side. Try pushing the black bit from the other side, it should open the valve.

 

But the seal looks pretty perished to me, probably time for a new unit anyway.

[wayned]

1 hour ago, ravip said:

I too understood the same as you mention. What confuses me is that the plunger is on the female side (the white 'rod' in the middle. Pressure from the male side only 'seals' it more.

From the picture, it's hard to see what side of the  valve seat that the valve closure flap is on.  If you stick something in the male side and press on the flap does it open?  If it opens then that's the side the input side.  If it doesn't, then the arrow is bass akwards and the female side is the input side.

[ravip]

Just now, Crossy said:

The white rod is on the outlet side. Try pushing the black bit from the other side, it should open the valve.

 

But the seal looks pretty perished to me, probably time for a new unit anyway.

Yes. This is old one. I was just wondering how it worked! Shall try what you mention.

[ravip]

Just now, wayned said:

From the picture, it's hard to see what side of the  valve seat that the valve closure flap is on.  If you stick something in the male side and press on the flap does it open?  If it opens then that's the side the input side.  If it doesn't, then the arrow is bass akwards and the female side is the input side.

Shall try that again.

[sometimewoodworker]

2 hours ago, ravip said:

I too understood the same as you mention. What confuses me is that the plunger is on the female side (the white 'rod' in the middle. Pressure from the male side only 'seals' it more.

The white rod is to locate the spring and is part of the plunger/seal which is under the yellow 3 hole plate which screws down and to hold the plunger against the rubber and stop flow from the female side to the male side.

 

So your last sentence it the exact opposite of the case.
 

Flow is (as the arrow) male to female and over pressure will lift the plunger 

[ravip]

Thank you very much indeed. Yes, in the new replacement part when you press from the male side it does open. Apparently the yellow lever on the replacement part is to check, when necessary, if the geyser contains water and has not run dry.

(Sorry, I am not in the location, hence I can't give first hand information)

[ravip]

Finally got the new unit to hand.

Yes, it opens in the direction of the arrow and closes on the reverse.

When the yellow lever is lifted, the small opening on the right angle part opens up from the arrow head side.