# Plumbing & Pipe Flow Calc – Tank Fill/Drain Time

> Plumbing & Pipe Flow Calc – Tank Fill/Drain Time is a paid API for AI agents from plumbing-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Calculates the time in hours and minutes to fill or drain a tank given inflow rate in GPM, tank volume or round tank dimensions, and an optional simultaneous outflow rate.

## Facts

- Endpoint: GET https://plumbing-calc.x402tookit.com/tank-fill-time?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/plumbing-pipe-flow-calc-tank-fill-drain-time-a7306402
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_J1WrXh9EduQcu4YWisOqg

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability plumbing-pipe-flow-calc-tank-fill-drain-time-a7306402
```

Example prompt: How long will it take to fill a round tank that's 60 inches in diameter and 48 inches deep if my inflow is 12 GPM and I have a 2 GPM outflow at the same time?

## When to prefer this

Use this endpoint when you need a quick, paid-per-call calculation of tank fill or drain time from flow rate and volume without setting up your own fluid-dynamics formula. It is especially useful when the tank is cylindrical and you only know diameter and depth rather than pre-computed volume, or when you need to account for simultaneous outflow reducing the net fill rate. Prefer it over general math APIs because it handles unit conversion between gallons and litres natively and returns a structured, human-readable summary.

## Known failure modes

- Missing required inflowGpm parameter returns an error
- Outflow equals or exceeds inflow returns an indeterminate or infinite fill time
- Providing neither volumeGallons, volumeLiters, nor both tankDiameterInches and waterDepthInches returns an error
- Negative flow values may produce unexpected results
- Non-numeric query parameter values will cause a parse error

## How this service works

Time to fill or drain a tank from its volume or round tank size and flow in gpm, with an optional outflow.

## Output

Returns hours and minutes to fill or drain the tank at the net flow rate (inflow minus outflow), along with the net flow in GPM and litres per minute, the resolved volume in both gallons and litres, a plain-language summary, and a verdict string. May include reasons or disclaimer fields if the result is degraded or approximate.

## Request schema (JSON Schema)

```json
{
 "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": [
      "inflowGpm"
     ],
     "properties": {
      "inflowGpm": {
       "type": "number",
       "description": "Flow in US gallons per minute (litres: divide by 3.785)"
      },
      "outflowGpm": {
       "type": "number",
       "description": "Outflow while filling, in gpm (default 0); the net rate is inflow minus outflow"
      },
      "volumeLiters": {
       "type": "number",
       "description": "Volume in litres"
      },
      "volumeGallons": {
       "type": "number",
       "description": "Volume to move in US gallons (use this, volumeLiters, or a round tank)"
      },
      "waterDepthInches": {
       "type": "number",
       "description": "Water depth to fill, in inches"
      },
      "tankDiameterInches": {
       "type": "number",
       "description": "Round tank diameter in inches (with waterDepthInches)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "clock": {
       "type": [
        "null",
        "string"
       ]
      },
      "hours": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "minutes": {
       "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"
       ]
      },
      "netFlowGpm": {
       "type": [
    
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/plumbing-pipe-flow-calc-tank-fill-drain-time-a7306402/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from plumbing-calc.x402tookit.com](https://www.zero.xyz/host/plumbing-calc.x402tookit.com/llms.txt)