Head loss in pipes is calculated by using the Darcy equation for newtonian fluids. But that seems like waaaaaaaaay overthinking it. On the scope and scale of MOST reef tanks we are talking tiny changes....so through a 1" union from 1" to 1" sch 40 PVC you should not lose enough head pressure to care about due to the union, it should be effected by the height/pitch/angle of pipe, a gate valve is a variable flow adjuster using a "gate", so I'm not sure what you mean, wide open it shouldn't effect flow directly, same goes for a ball valve. Let's say the gate valve is 50% open, so you are cutting 1/2 of your flow rate (not pressure per say)...the math is starting to get complicated. A T is techincally 2 90 degree turns, so my assumption would be double the 1/2 foot of pressure added per 1" elbow pipe....so 1 foot of pressure. What are you trying to figure out? Please don't make me dig out my math books. Its only tuesday. I would call a plumber if you have something wild going on. Again, normal reef tank stuffs we usually don't have toooooo much to worry about. Have you tried the Pentair calculator yet???? https://pentairaes.com/pump-calculator
No, I will try that calculator. I'm trying to set up a new tank build. I haven't touched a tank in about 5 years now because I moved from AZ to WI and gave my tank away before I moved. But I've read a lot on this site about pressure loss from the pump to the display tank. Almost every reply I see from people asking why they're pressure is so low to others is, what's your head loss through pipes and fittings etc... well when I tried to research head loss through fittings there isn't much out there besides 90 and 45 degree fittings. Thank you for your reply though.
Once you know size of sump, size of DT, desired flow rate you can pretty much figure it out pretty easy. Always buy a bigger pump than you think, and if you can a DC pump that's variable. I shoulda got a bigger sized one (it's fine) and I do agree the check valve cut down my flow a bit, I probably would not repeat that in future plumbing.
Thank you, that helps quite a bit.Not much head loss through a union or fully open ball or gate valve, but when you begin to close those of course you will get less flow. According to a LSS book I have you loose and equivalent length of straight pipe of 2.5' for a 90 elbow and 1.7' for a tee that runs and 6.0' for a T that branches. How many GPH all of that equates to would depend on your pumps operational curve at various head pressures.
So, if I had a T from my return line going to a manifold and the rest continuing to display is that considered a branching T? One other question as well, is your head loss only calculated from the return side of the pump to the display?
One more question, what would the loss to straight pipe be for a 1 1/4" to 1" reducer on the return line side of the pump?Not much head loss through a union or fully open ball or gate valve, but when you begin to close those of course you will get less flow. According to a LSS book I have you loose and equivalent length of straight pipe of 2.5' for a 90 elbow and 1.7' for a tee that runs and 6.0' for a T that branches. How many GPH all of that equates to would depend on your pumps operational curve at various head pressures.
