Diy spray bar! I need help!

[MikeJojo]

That's correct calculation, but do not go for 70 holes of 3mm diameter because there will be not much velocity.

Edit: I made a spray bar once with over 50 holes of 2mm diameter and velocity was not good really.

 

[MikeJojo]

Guys, I've just received another two pieces of 1m acrylic tubes from www.trentplastics.co.uk and will be doing another spraybar but this time with 5mm holes. I need to do 9 holes. Hopefully this time I'll be happy with velocity and all streams will be reaching front glass.

 

[Gilles]

That's correct calculation, but do not go for 70 holes of 3mm diameter because there will be not much velocity.

Edit: I made a spray bar once with over 50 holes of 2mm diameter and velocity was not good really.

Won't the velocity be the same as with 1x 25mm output (since surface is equal)?
What would be your suggestion?

 

[ceg4048]

Hi Gilles,
I'm really not sure about your hose calculation. Is 25mm the outer diameter or is it the inner diameter? The area we're talking about is the area that the water flows through and does not include the tube's wall thickness.

I'm not sure why there's a need to guess. Just pick the number of holes you want to drill. If you pick 70 holes then each hole must have a cross sectional area of 490/70 = 7 square mm.

Each hole that you add increases the friction and lowers the pressure as the water pours out so there is some loss there and you want to avoid having a lot of holes, but basically it's as you described.

Cheers,

 

[MikeJojo]

Won't the velocity be the same as with 1x 25mm output (since surface is equal)?
What would be your suggestion?

Area must be the same but let's take for example single hose of 25mm and run water. If you put your hand against it you will feel much force/ pressure on your hand. If you add spray bar with ie 20 holes size of 5mm then if you put your hand against one single hole you won't feel the same amount of force.

That's what happens in aquarium.

More small holes = less velocity

Less but larger holes = more velocity

People play with number and size of holes to achieve strength of flow that works best in their aquariums.

I'm doing I think 5th spray bar now but this time with 9 holes of 5mm in size.


Hope it helps.

Mike


Sent from my iPhone using Tapatalk

 

[Gilles]

I will be making two versions of 25mm piping;
1 with 5mm holes (20 square mm) and 25 holes.
1 with 6mm holes (28 square mm) and 17 holes.

If i read ceg correctly, you'd want the streams to hit the front glass, then it is mission accomplished

 

[Edvet]

You might even want to start with not all the holes made, easier to add holes then to plug them.

 

[Gilles]

good advice Ed