Pipes & Pressure
Acoustic Flow Meter Design
V = L · (t₁ − t₂) / (2 · t₁ · t₂ · cosθ)
Pipe flow velocity from upstream and downstream ultrasonic transit times.
Design →Aluminum Pipe Design
P = 2 · S · t / D
Working pressure rating from wall thickness, allowable stress, and outside diameter.
Design →Buried Corrugated Pipe Design
P_total = soil + live + frost
Combined external pressure load on buried corrugated metal pipe at design depth.
Design →Buried Plastic Pipe Design
P = γ · h + W_L / A
Soil + surface load on buried PVC or HDPE pipe at design depth.
Design →Buried Spiral Rib Pipe Design
P_total = P_soil + P_live
Combined load on buried spiral-rib metal pipe at design depth.
Design →Ductile Iron Pipe Design
P_design + thrust restraint
Wall thickness, pressure rating, and thrust forces for ductile iron water mains.
Design →Pipe Hydrostatic Pressure Load
P_ext = γ_w · h
External hydrostatic pressure on a buried pipe at a target water-table depth.
Calculate →Pipe Soil Pressure Load
P_soil = γ_soil · h
Vertical soil pressure load on a buried pipe from overburden weight.
Calculate →Pipe Vacuum Pressure Load
P_vac = P_atm − P_internal
Vacuum load on a pipe carrying gas or under partial-vacuum service.
Calculate →Pipe Wheel Loading
W_l = 0.64 · P_l · IF / h (deep cover)
Merritt wheel load and pipe pressure from live load, cover depth, and pipe diameter.
Calculate →Plastic Pipe Design
P_rated = 2 · HDB · t / (SDR − 1)
C900 PVC pressure class from hydrostatic design basis and dimension ratio.
Design →Smooth Wall Steel Pipe
P = 2 · S · t / D
Working pressure rating for smooth-wall steel pressure pipe per AISI.
Design →Thrust Block Design
A = T / (S_b · SF)
Bearing area of a concrete thrust block at a pipeline bend, tee, or dead end.
Design →Unconstrained Restrained Pipe Expansion
ΔL = α · L · ΔT
Unrestrained linear expansion of a pipe between operating and reference temperatures.
Calculate →Pipe design and pressure-load calculators covering aluminum, plastic, steel, ductile iron, and buried pipe systems. Includes pressure rating, soil pressure load, hydrostatic load, vacuum load, wheel load (live load), and unrestrained pipe expansion.
Used by civil and mechanical engineers for water mains, sewer lines, irrigation, and process piping design. Formulas track AWWA, ASTM, and AISI design standards.
When to use these calculators
Use the pipe pressure-rating calculators to verify wall thickness against operating pressure for a given pipe material. Use the buried-pipe loading calculators (corrugated metal, plastic, ductile iron, spiral-rib) to check that the pipe can support overburden + wheel + frost loads at the design depth. Use the thrust-block calculator to size concrete reaction blocks at bends and tees on pressurized lines.
These are educational tools — always verify against current design codes and consult a licensed engineer for production piping designs.
Frequently Asked Questions
- What pipe materials are covered?
- Aluminum, plastic (PVC, HDPE), spiral-rib metal, corrugated metal, ductile iron, and smooth-wall steel are each handled by a dedicated calculator with material-specific allowable stress and wall-thickness equations.
- How are buried-pipe loads computed?
- Soil pressure load uses unit-weight × depth; wheel load uses the AASHTO impact-factored point load distributed via Boussinesq theory. The buried-pipe family combines soil + live load and compares to the pipe's pressure rating to give a safety factor.
- When do I need a thrust block?
- Pressurized water mains need thrust blocks at every bend, tee, valve, and dead end to resist the hydraulic reaction force. The Thrust Block calculator sizes the bearing area against soil allowable bearing pressure.