CV valves - label examples

The markings for CV valves are specified in document K1001 and also here. Below are images of a few of the CV valves in the collection along with their meanings.

	A 'classic' marking, YL is the date code (L=december, Y=1966), KB/F means a valve made to specification K1001 or K1006 (K) and approved by a UK authority (B). The valve was made in the STC Paignton factory (F)
	Similar to the above example, this time a valve made to K1001/K1006, UK approved, in January 1957 at AEIs Leicester facility.
	Similar again, this time the date code (KK) is rotated to save space.
	A different layout, the date code and 'broad arrow' appearing on top.
	A more complex example, the date code here is the 4-digit variant, 6901 meaning the 1st week of 1969. What complicates this mark is the original valve has been modified and re-labelled as CV2012.
	Here, the valve shows both CV and civilian type markings, a 4-digit date code, but no other information. Given the order of preference is CV number, factory code and date code, there is no factory code present.
	In this example the valve carries a 2-letter date code and the CV number, but the approving agency is missing after the K. RC indicates the valve was made by Ferranti.
	Another example of missing information, this time neither the specification or qualification letter is present.

Finally, some valves only ever get the CV number and no other 'relevant' markings