Valve Guard, Valve Guard Ring, Collar, Foot Ring, Base Ring, Base,Bottom Dish End

Foot Ring/Base Ring/Base
Definition:
A circular steel ring fitted and welded onto the bottom dish end of the cylinder, acting as the stable support base for the whole gas cylinder.

Cylinder Body 
Definition:
The main cylindrical straight middle section of the LPG pressure vessel, the primary bearing component that stores liquefied petroleum gas under pressure.

Dome/Top Dome
Definition:
The curved hemispherical or dished upper end cap welded to the top of the cylinder body. It has a central threaded opening for installing the gas valve.

Dish Ends/Bottom Dish End
Definition:
The curved dished bottom closing component welded to the lower end of the cylinder body, forming the sealed bottom cavity of the cylinder.

Distinction note
Dome = upper curved head (valve side)
Dish ends = general term for both top and bottom curved heads; often specifically refers to the bottom base head in factory production

Halves 对半分体封头（分体式封头）
Definition:
Short for split dish halves / two-piece dished heads. It refers to semi-circular curved steel half-pieces that are assembled and welded together to form a full dome or dish end, widely used in small and medium LPG cylinder manufacturing.

Application:
Manufacturers cut steel plates into two symmetrical curved halves, then circumferentially weld them to make a complete end cap before attaching to the cylinder body.

Full Integrated Paragraph (for technical documents / product catalogs):
Major structural fittings for liquefied petroleum gas (LPG) welded steel cylinders include the valve guard ring (also called collar), foot ring (or base), cylinder body, dome, dish ends and split dish halves. The collar/valve guard ring is welded to the top dome to protect the cylinder valve from external impact, another function of the collar/valve guard ring is for lifting and transporting gas cylinders. The foot ring, known as base, is fixed to the bottom dish end to support the cylinder upright and reduce ground abrasion, this foot ring has additional functions, such as draining moisture and keeping the bottom of the gas cylinder ventilated and dry. The cylinder body is the straight main cylindrical shell for gas storage. The dome is the curved top head with a valve mounting hole, while dish ends represent the full curved closing heads at both ends of the cylinder. Halves refer to two-piece semi-circular steel blanks that are welded into complete dish ends during cylinder production. All these parts are welded together to construct a complete pressure-bearing LPG cylinder.