Rule of Thumb for Flow Rate Through Hospital Sanitary Line

[bvelazquez]

is there a rule of thumb for calculating the flow rate of sanitary sewer through a hospital sewer line? For example, X gallons per day per number of beds in a hospital. As a structural engineer, building codes typically have tables listing what loads are to be used for the design of hospital floors, libraries, offices, etc. etc. I was wondering if for plumbing design there was something similar for estimating the size and flow rate through pipes. Thanks.

 

[CRG]

Kinda, the plumbing codes use fixture units and tables for sizing sanitary waste lines.

 

[friartuck]

Sanitary flow rates are estimated using diversity or simultaneous demand tables.

Years ago the Institute of Plumbing used to work on a simple rule of thumb where you totalled the appliances (say 100) and you found the sq.rt. i.e. 10. This gave a quick guesstimate on the number of appliances that would be in use at any one time.

Nowadays, the simultaneoud demand tables yield slightly different results...but not usually that far out.



Friar Tuck of Sherwood

 

[saxon]

bvelazquez, The estimating factor used in the Chicago area for sanitary sewer sizing is 25 gpd per person. Now all you need is to estimate the building/area occupancy. Or you can use the fixture unit value approach.

As for line sizing, the building code has tables based on flow and slope.

Hope this helps.
saxon

 

[skier59]

Wastewater Engineering, 3rd Ed, Metcalf & Eddy, lists a wastewater flow of 130 - 260 gpd/bed, with a typical value of 150 gpd/bed.

 

[nackra]

I used "Practical Plumbing Design Guide" by James Church when working on remodel of one floor of hospital in Illinois in early 80's. I suspect that there are newer editions.

I worked on sizing air, vacuum, gas, HW, HWR, CW piping based on this reference.

Good Luck