The top two images right, show the two states of the 'inlet valve' - valve open, Fig1 and valve closed, Fig2.
When the handle of the 'lifting rod', and attached 'lifting valve' assembly is raised, a lower than atmospheric pressure is created inside the 'lifting tube', between the two valves.
The lower pressure causes the 'lifting valve', attached to the 'lifting rod', to close, as shown in Fig3, right.
Atmospheric pressure acting on the spirit causes the 'inlet valve' to open, as shown in Fig1, right, admitting spirit to the lifting tube - in the space between the two valves. The moving part of the 'inlet valve' opens as far as the retaining nut allows.
At the top of the stroke, the pressures are equal, and the 'inlet valve' closes, as shown in Fig2, right.
The down stroke starts to pressurise the spirit in the 'lifting tube', between the two valves, keeping the 'inlet valve' closed, as shown in Fig2, right. The moving part of the 'inlet valve' seats into the chamfered valve body.
The continued down stroke and pressurisation of the spirit in the 'lifting tube', causes the 'lifting valve', attached to the 'moving rod', to open, as shown in Fig4, right, allowing the spirit trapped between the two valves to enter the 'lifting tube', in the space above the 'lifting valve'. The moving part of the 'lifting valve' opens as far as the retaining nut allows.
At the bottom of the stroke, the pressures are once again equal, both the 'inlet valve' and the 'lifting valve' will be closed.
A head of spirit is now in the 'lifting tube' above the 'lifting valve'.
At the next up stroke, the spirit above the lifting valve is moved up into the bowl and out of the spout, into the waiting measure.
At the same time, the cycle begins again.
Inlet valve attached to lifting tube. Centre punching to retain nut.
Inlet valve disassembled.
Situated at the bottom end of the 'lifting tube', the 'inlet' valve allows rum to enter the 'lifting tube' when the handle of the 'lifting rod', with the attached 'lifting valve' assembly, is raised.
All parts of the 'inlet valve' are constructed from brass.
The 'inlet valve' is threaded and screws into a matching collar brased into the bottom of the 'lifting tube'.
To effect a seal, a leather washer should be in place between the collar of the 'inlet valve' assembly and the bottom of the 'lifting tube'.
The image below left, shows the 'inlet valve' assembly attached to the bottom of the 'lifting tube', while the image below, centre, shows the moving part of the 'inlet valve' removed from the body, to show components parts.
The bottom of the 'inlet valve' moving part is threaded and takes a 5/16" BSW brass nut. In operation, the nut was prone to come loose and fall off.
One solution was to 'centre punch' the end of the 'inlet valve' moving part once the retaining nut was fitted, thus spreading the end of the thread and keeping the nut in position - this can be seen in the image below right.
Spout brazed to the bowl externally. Brass collar at the lifting pipe / bowl junction.
'Tinning' to the inside of the pump bowl.
The image immediate left, shows a brass connecting collar between the lifting tube and the underside of the bowl.
Not all pumps have the brass collar, some have a similar arrangement made from copper.
The elongated lifting tube can be seen in the two images above. The lifting tube, bowl and spout are constructed from copper, usually, all three components are 'seamless', however, one of my collecting colleagues has a pump with a seamed spout.
The lifting tube, bowl and spout are all 'tinned' internally.
'Tinning' to the inside of the bowl is shown in the image left.
The bowl shape remains fairly constant, although one unusual variant is shown later in the page.
The spout length, angle of descent and fixing method to the bowl, does vary across a number of pumps, likely due to a number of different manufacturers over a period of years. The image below left, shows the flange of the spout assembly, it is brazed to the outside of the bowl. Quite a common variant has the spout assembly brazed to the inside of the bowl.
Rum pump - Handle, bowl and spout.
Commonly referred to as a 'rum pump', the Royal Navy 'spirit pump' changed little from the start of the photographic record, to the cessation of the rum issue in 1970. My collection shows a number of minor variations from pump to pump, but the basic design remains the same.
Rum Pump - complete. Rum Pump - gear removed.
Royal Navy spirit ( rum ) pumps.
I mentioned earlier in the page that the Rum Pump bowl shape remained fairly constant over a number of years and differing manufacturers.
The image right shows a pump with quite an unusual bowl shape, more square at the bottom rather than rounded.
The spout of this pump is also unusual as it exits the bowl almost horizontally.
Image provided by kind permission of Mr Geoff Pringle of oldnautibits.com
The image left, shows the marks impressed into one of my own pumps.
1956 is the year of manufacture.
53598 is the Vocabulary number - a stores identification number.
Vocabulary numbers were applied to Naval equipment from the early 1950's.
The 'craftsman' like image in the centre, is the 'trade mark' of the manufacturer.
It is unusual to find a pump with a makers mark or vocabulary number, I make the assumption therefore, that most pumps pre date the 1950's.
Vocabulary number applied to the bowl.
Lifting valve attached to lifting rod
Lifting rod attached to wooden pump handle.
Lifting valve dissassembled.
The image left, shows the 'lifting valve' unscrewed into it's component parts.
The valve moving part is at the bottom of the image.
The moving part is held captive inside the bottom half of the valve - left hand side of the image - by a 3/16 BSW nut.
The leather 'cup washer' also fits over the threaded section of the bottom half of the valve.
The 'cup washer' is held captive by the upper part of the valve - right - being tightened down onto the lower part of the valve - left.
Handle, Rod and Lifting Valve:
Lifting valve closed. Fig3.
Lifting valve open. Fig4.
Inlet valve closed. Fig2.
'Flats' carved into the underside of the handle.
The image below left, shows the the 'lifting valve' attached to the brass lifting rod, while the image right shows the lifting rod attached to the pump wooden handle.
The image below centre, shows how some handles had 'flats' carved to the underside, presumably to give a better 'seat' of the handle on the bowl rim?
Located at the bottom end of the 'lifting rod', the 'lifting valve' creates the pressure differential inside the 'lifting tube' when the wooden pump handle is cycled.
All metallic parts of the 'lifting valve' are made of brass.
The 'lifting valve' is threaded and screws onto the 'lifting rod', which is also made of brass. The 'lifting rod' is attached to the wooden pump handle.
To create a seal between the 'lifting valve' and the walls of the 'lifting tube', a leather 'cup washer' is held captive between the two halfs of the 'lifting valve' assembly, kept flexible, by daily contact with the spirit.
The whole assembly is pushed into the 'lifting tube' through the bowl, the handle coming to rest on the bowl rim.