Capillary action
In plumbing · also called Capillarity
Movement of liquid in a narrow space caused by surface tension and interactions with the surrounding material. A thin tube can show water standing above the main surface. This effect differs from the level-driven flow of a siphon.
Using Capillary action in a plumbing system
Updated
A distinction worth remembering
Dimensions, mass, temperatures and time must use consistent units. State the assumptions behind a simplified water-heating or pipe-volume result, then identify whether losses, extra components or a change of phase would require a broader model.
Questions to take further
- Why can a correct number still be a poor design answer?
- The arithmetic may be correct for only part of the system. Missing water volume, unmeasured operating conditions or omitted heat losses can make the model incomplete.
Sources
- Skills England: plumbing and domestic heating technician — The systems, materials, planning and customer responsibilities in the England occupational standard.
Where Capillary action fits in the learning path
The Plumbing Basics section covers these topics:
- Water in a Home
- Meet the plumbing trade and routes in
- Science and calculations for plumbers
Read, practise, return
1. Read it in context
- Science and calculations for plumbersPlumbing Basics
2. Try recalling, then explore practice
Use the memory prompt below to connect the vocabulary.
3. Return to the meaning
After reading or practising, explain the idea in your own words, then check what you remembered.
Recall a related term
Which term fits this definition? Say it to yourself, then reveal it. This is a memory prompt, with no score or saved result.
The loss of water from a trap when moving water lowers the air pressure behind its seal. Self-siphonage comes from the appliance's own discharge running full bore; induced siphonage comes from another appliance's flow passing through a pipe the trap shares.
Siphonage
Read the Siphonage entryCompare related terms
Open a meaning to compare its role with Capillary action, or follow its full entry.
Siphonage
The loss of water from a trap when moving water lowers the air pressure behind its seal. Self-siphonage comes from the appliance's own discharge running full bore; induced siphonage comes from another appliance's flow passing through a pipe the trap shares.
Read the Siphonage entryFlow rate
How much water comes out of an outlet in a given time, usually measured in litres a minute by timing how long a container of known size takes to fill. It is different from pressure: a supply can have good pressure and poor flow if a pipe is narrow, partly blocked or shared with other outlets.
Read the Flow rate entryBefore you start: some plumbing work is regulated or notifiable
Some water fittings work needs notice to, and consent from, the water supplier before it starts. Check the rules where you live.
Gas work is for competent workers covered by a Gas Safe registered business in Great Britain. Northern Ireland has separate gas regulations. Do not work on gas pipes or appliances yourself.
In England, installing an unvented hot-water system over 15 litres is notifiable building work: use a competent installer registered with a competent-person scheme, or tell building control before work starts. Leave this work to a suitably skilled person.
Wales, Scotland and Northern Ireland have their own water and building rules; check which apply before work starts. Electrical connections belong with an electrician.
This guide does not qualify you or make you competent, approved or registered for plumbing, gas or unvented work.
A definition is a start. Using it in a real question is where it sticks.