
1) Cutoff points 2) Parts of hearts 3) Sluice gates 4) Trumpet features 5) Trumpet pieces 6) Trumpet tone-changers
Found on
https://www.crosswordclues.com/clue/valves

Valves are used in most types of bagpipes to close off the air entry point (the blowpipe), although some pipers simply closed the end of their blowpipe when they took a breath.
Found on
http://en.wikipedia.org/wiki/Glossary_of_bagpipe_terms

(Life processes and cells) structures containing a flap or flaps to ensure one-way flow of liquid
Found on
http://www.encyclo.co.uk/visitor-contributions.php

Larger veins in the body have valves that control the flow of blood. These valves assist in transporting the blood against the pull of gravity back to the heart and lungs. In the deep leg veins, the valves occur every twelve millimetres along the legs. Some activities and habits, such as crossing the legs a lot and spending too much time on the fee...
Found on
http://www.probertencyclopaedia.com/browse/EV.HTM

In a combustion engine, an intake or exhaust valve usually consists of a disk with a stem, which is opened by a cam and closed by a spring.Also, it signifies the total intake and exhaust valves in an internal combustion engine. For example, a 24-valve V-6 would have 4 valves per cylinder 24/6=4. A 16-valve V-8 would have 2 valves per cylinder 16/8=...
Found on
https://www.encyclo.co.uk/local/20687

paired, hard shells, for example in bivalves
Found on
https://www.encyclo.co.uk/local/20800

Many overhead-cam engines, particularly multi-valve models, are described by the total number of intake and exhaust valves in the cylinder head. A 24-valve V-6 engine would have four valves per cylinder: two intake and two exhaust valves. A 16-valve V-8 engine has only the standard single exhaust and single intake valve for each of its eight cylind...
Found on
https://www.encyclo.co.uk/local/22335

Connected to an inner tube. Protrudes through the rim and permits inflation. Either presta or schrader.
Found on
https://www.encyclo.co.uk/local/22521
No exact match found.