{"uid":"cap_eXlHB2_5cc7RLkpynFNNy","slug":"plumbing-pipe-flow-calc-flow-velocity-e5abcbfd","name":"Plumbing & Pipe Flow Calc – Flow Velocity","description":"Water velocity in feet per second from flow in gpm and pipe size, or the flow a pipe carries at a chosen velocity.","url":"https://plumbing-calc.x402tookit.com/flow-velocity?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":[],"properties":{"flowGpm":{"type":"number","description":"Flow in US gallons per minute (use flowGpm or velocityFps)"},"material":{"type":"string","description":"copper-l or pvc-40 (default copper-l)"},"nominalSize":{"type":"string","description":"Nominal size such as 3/4 (with material), or insideDiameterInches"},"velocityFps":{"type":"number","description":"Velocity in feet per second, to get the flow"},"insideDiameterInches":{"type":"number","description":"Inside diameter in inches"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"asOf":{"type":["null","string"]},"pipe":{"type":["null","string"]},"source":{"type":["null","string"]},"flowGpm":{"type":["null","number"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"disclaimer":{"type":["null","string"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"flowAreaSquareFeet":{"type":["null","number"]},"flowLitersPerMinute":{"type":["null","number"]},"insideDiameterInches":{"type":["null","number"]},"velocityFeetPerSecond":{"type":["null","number"]},"flowCubicFeetPerSecond":{"type":["null","number"]},"velocityMetersPerSecond":{"type":["null","number"]}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_ASsMXxnkEoBs-CHsM9kbg","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates water velocity in feet per second from flow rate and pipe size, or calculates the flow a pipe carries at a given velocity, for copper Type L or PVC Schedule 40 pipe.","exampleAgentPrompt":"What's the water velocity for a 3/4 inch copper Type L pipe flowing at 8 gpm?","exampleUseCases":[{"title":"Residential plumbing velocity check","prompt":"I'm sizing a water supply line — what velocity will I get with 6 gpm through a 1/2 inch copper Type L pipe?"},{"title":"PVC irrigation line flow rate","prompt":"If I want water moving at 5 feet per second through a 1 inch PVC Schedule 40 pipe, how many gallons per minute does that work out to?"},{"title":"Custom pipe diameter calculation","prompt":"I have a pipe with an inside diameter of 1.05 inches and I'm pushing 10 gpm through it — what's the velocity in feet per second?"}],"resultDescription":"Returns an object with velocity in feet per second and meters per second (or flow in GPM and liters per minute if velocity was the input), along with inside diameter in inches, flow area in square feet, flow in cubic feet per second, a text summary of the result, the pipe description, and a disclaimer. Also includes degraded flag and any reasons or notes about the calculation.","failureModes":["Missing both flowGpm and velocityFps — exactly one must be provided","Missing both nominalSize/material and insideDiameterInches — one must be provided to identify the pipe","Invalid material string not matching 'copper-l' or 'pvc-40' may produce an error or fall back to default","Non-standard nominal size string that doesn't match known pipe tables may return an error","Providing both flowGpm and velocityFps may cause ambiguity or an error","Very large or zero flow/velocity values may return degraded results"],"whenToPreferThis":"Use this endpoint when you need to compute water velocity from a known flow rate and pipe size, or to find the flow rate that corresponds to a target velocity in a standard copper Type L or PVC Schedule 40 pipe. It is the right choice for residential or light commercial plumbing design, irrigation system checks, or any hydraulic calculation involving standard US pipe sizes. Prefer it over pressure-loss or pipe-sizing sibling endpoints when your primary question is specifically about velocity or flow rate in an already-known pipe.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T13:08:11.104Z","isFirstParty":false,"canonicalSlug":"plumbing-pipe-flow-calc-flow-velocity-e5abcbfd"}