Pressure And Bld'g. Ht. Question

Posted by Robert11 on February 21, 2009, 4:40 pm

Hello,

Let's say that the pressure reducer for an incoming water line to a
residential house is set
at 50 psi, and that it works "perfectly" in that it will always keep the
downstream p at the reducers exit at exactly 50 psi.

Two floors above there is a shower. (not running)
Assume 17 feet higher than the p regulator.
If we take 34 feet of "head" as being 15 psi, then 17 feet of head is about
7.5 psi.

Would the (static) pressure at the shower head be, therefore just 50-7.5 =
42.5 psi ?

Thanks,
B.

Posted by geothermaljones on February 23, 2009, 12:13 am

First, your building has some really low ceilings.
Second, are you sizing shower valves or what???
Now considering the valve is 18" AFF, & the shower head is 6.5' AFF (above
finished floor) then,
Third, could you rinse the soap off your jack handy on the 20th, 21st or
22nd floor?
(If, of course, your willing to wait)

geothermaljones

> Hello,
> Let's say that the pressure reducer for an incoming water line to a
> residential house is set
> at 50 psi, and that it works "perfectly" in that it will always keep the
> downstream p at the reducers exit at exactly 50 psi.
> Two floors above there is a shower. (not running)
> Assume 17 feet higher than the p regulator.
> If we take 34 feet of "head" as being 15 psi, then 17 feet of head is
> about 7.5 psi.
> Would the (static) pressure at the shower head be, therefore just 50-7.5 =
> 42.5 psi ?
> Thanks,
> B.
>

Posted by Don Ocean on February 23, 2009, 2:35 am

geothermaljones wrote:

> First, your building has some really low ceilings.
> Second, are you sizing shower valves or what???
> Now considering the valve is 18" AFF, & the shower head is 6.5' AFF (above
> finished floor) then,
> Third, could you rinse the soap off your jack handy on the 20th, 21st or
> 22nd floor?
> (If, of course, your willing to wait)
>
> geothermaljones
>
>
>

>> Hello,
>> Let's say that the pressure reducer for an incoming water line to a
>> residential house is set
>> at 50 psi, and that it works "perfectly" in that it will always keep the
>> downstream p at the reducers exit at exactly 50 psi.
>> Two floors above there is a shower. (not running)
>> Assume 17 feet higher than the p regulator.
>> If we take 34 feet of "head" as being 15 psi, then 17 feet of head is
>> about 7.5 psi.
>> Would the (static) pressure at the shower head be, therefore just 50-7.5 =
>> 42.5 psi ?
>> Thanks,
>> B.

static pressure? How about equal through out. Maybe you should worry
about dynamic pressure. Better yet.. Just measure it and be done with
the niggling formulizations. No real engineer ever trusts the figures
without a hands on test. Unknown variables can and do occur.

>
>

Posted by on February 23, 2009, 2:44 am

wrote:

>geothermaljones wrote:

>> First, your building has some really low ceilings.
>> Second, are you sizing shower valves or what???
>> Now considering the valve is 18" AFF, & the shower head is 6.5' AFF (above
>> finished floor) then,
>> Third, could you rinse the soap off your jack handy on the 20th, 21st or
>> 22nd floor?
>> (If, of course, your willing to wait)
>>
>> geothermaljones
>>
>>
>>

>>> Hello,
>>> Let's say that the pressure reducer for an incoming water line to a
>>> residential house is set
>>> at 50 psi, and that it works "perfectly" in that it will always keep the
>>> downstream p at the reducers exit at exactly 50 psi.
>>> Two floors above there is a shower. (not running)
>>> Assume 17 feet higher than the p regulator.
>>> If we take 34 feet of "head" as being 15 psi, then 17 feet of head is
>>> about 7.5 psi.
>>> Would the (static) pressure at the shower head be, therefore just 50-7.5 =
>>> 42.5 psi ?
>>> Thanks,
>>> B.

>static pressure? How about equal through out. Maybe you should worry

Actually, the static pressure will decrease with the height of
the column. Remember, this is water, not air. The weight is still
there, and the pressure at the base of the column will be greater than
it is at the top, regardless of whether that top is open ( thus a
dynamic situation ) or sealed ( a static situation ).

--
Click here every day to feed an animal that needs you today !!!
www.theanimalrescuesite.com/

Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo online at www.pmilligan.net/palm/
Free 'People finder' program now at www.pmilligan.net/finder.htm

Similar Threads	Posted
Flow / Pressure Question	January 5, 2008, 6:24 pm
Question re Gas Furnace Pressure Switch	January 4, 2008, 6:45 pm
Watts Water Pressure Reducing Valve Question	May 5, 2009, 7:23 am
Boiler Pressure	June 2, 2007, 8:29 am
Pressure switch	March 1, 2008, 9:01 pm
pressure switch on gas furnace	October 18, 2006, 1:28 pm
PRESSURE SWITCH INQUIRY	November 27, 2006, 11:21 am
Furnace pressure problem	March 16, 2007, 12:04 pm
Who's got one of these? (Amana pressure switch)	February 12, 2008, 7:12 pm
Air enthalpy pressure charts.	January 4, 2009, 5:16 pm