Steaming and pressurising

Pressure-stat back in stock £14.50 plus postage

LeFoo LF25 

These are an exact replacement for the XP110. They have proved to be very reliable with no reported field failures to date. Pressure preset to 0.9bar. Great price too!

Single Hole Steam Wand Nozzle

I am not sure about these yet but people seem to like them. I have been asked a lot about substituting the La Pavoni three hole nozzle for a single hole version. I have made some and have a few left if you would like one. In plated brass or stainless steel £3,50 inc postage in UK. 

Pressure-stats

The Signallux M3 pressure stat was changed to XP110 from MA-TER see diagrams and data sheets (click on relevent photo below).

I think it is because (apart from any cost considerations) the adjustment ring on the M3 is VERY easily broken, It is just plastic and is locked with a locking compound after factory setting. If you have to make any adjustment first make sure the copper pipe is completely free of scale using a flexible wire (a low E string from a guitar works well) and there is no flattening of the tube due to previous attempts to bend the tube. if there are any flattened sections, use mole grips and aluminium sheet to act as "soft jaws" to avoid damaging the copper. Once this is done, clear away the white compound with a sharp blade before trying to adjust the M3. Add a little WD40 to the threads and grip the adjustment ring with a rag and turn a little at a time. If it will not move don't over-force it, go back and clear away as much compound as accessible and try again - don't rush or you will break the adjuster ring and render the stat useless.

There is also a cross headed eccentric peg passing through the body of the microswitch which can give a little fine adjustment to the deadband (I know it as hysteresis) of the stat. This is the pressure difference between the switch on and switch off of the stat. The stat can be balanced by the adjustment ring and cross head peg adjustment. If that does not work, do try replacing the microswitch before buying a complete new stat (worth trying for a few pounds). Try Maplins - you will need a Cherry 45X or equivalent

XP110

I have been testing an equivalent to the XP110 for about 2 years now and can vouch for their reliabilty It's a LeFoo LF25

Here is the early pressure-stat from the original Professional model, can be a bit temperamental as they wear.

The pressure-stats are normally pre-set and if you buy a new one you just need to fit it. Sometimes however in an attempt to adjust (mainly due to scaling problems or element failure), the setting is lost. This not a problem if it is a Professional or a Europiccola with a gauge conversion,

The copper stat pipes sometimes split or crack when trying to remove. It is a must to anneal the copper pipe before rebending (if you remove the heating element/base/boiler for example). Sometimes there are problems if it is from a very old machine (gets very brittle) or it has been overstressed by previous attempts to bend the pipe.

It is very important that you do not flatten the pipe while bending as it will allow scale to collect and quickly block the operation of the stat. Use a round bar or similar to support the tube while bending (take care, especially the area where the pipe exits the flanged connector in the heater plate)

Example of a broken pressure stat tube

Alternatives

I have been experimenting with a 6mm teflon replacement of the OEM copper stat pipe using screw quick fit connector male 1/8" BSPT for heating element connection and a 1/4" BSPP female for the pressure stat. You will need copper or teflon sealing washers to get a steam tight seal at the stat. Do not use standard Dowty washers unless you can find a teflon version. Available from manufacturers Aignep and Cammozzi (1000 series). Use an elbow for the male fitting if you can as it allow less bending of the teflon pipe to fit onto the base of the machine (easy if replacing with the bolt in element but more difficult if not as there may not be enough clearance between the element and the pressure pipe entry on the base).

1/8" BSPT for the element plate connection

 1/4" BSPP pressure stat connector

TIP use a piece of sandpaper to grip the teflon tube when pushing it onto the connectors. Don't forget to slide the nut onto the pipe first. If you have to remove the pipe for any reason, undo the nut and pull the pipe out, cut off the last 5mm or so and then refit. Do not over-tighten.

I have had a teflon tube based stat set up in my bench machine for a few months now with no apparent leakage. It is far easier to orientate than copper tube. If you want to keep it traditional, this method could also be used for 6mm copper pipe by substituting 6mm brass pneumatic compression joints (Wade or Aignep)

Pressure Gauge fitment to Europiccola

In an attempt to stop retrofitting of pressure gauges to Europiccola pressure-stat models, La Pavoni changed the thread to M11 from M12 and the M11 adaptors are no longer available as a spare (I am sure it is to keep the price differential between models). I have been trying to find a source of M11 to 1/8" BSP adaptors but the tooling costs are too high to be viable. here is my DIY fix -drill out the M11 thread in the top sight glass shoulder with an 11mm drill and tap with an M12x1.0. Only remove the thread depth do not drill through the cpmplete shoulder. You can get away with a plug tap (bottoming tap) but it is easier to use a second (taper) tap to start the thread. The currently available OEM M12 adaptors will then fit the sightglass shoulder.

I made a jig to support the shoulder while drilling. you can take the shoulder off for drilling but the nut is very akward to get at. There is not a lot of material to remove so it should not be a problem without a jig but do make sure the shoulder is not twisted and is completly vertical or the drill will "snatch"

I used a bench press but it should be possible with care to use a hand drill.

Use cutting oil when drilling and tapping. Half to a full turn and reverse to break off any swarf from the cutting of the thread

Boiler leaks and Safety valve operation

I pressurise the lever machines to check for leaks if I dismantle any part of the tank or suspect a leak. It was pretty impossible to check with steam (unless of course it was a gross leak) due to the temperature. 

I have a woods valve taken out of an inner tube, 6mm pressure hose and a hand pump of course. Open the steam tap, pressurise, close the tap and check for leaks.

I bypass the pressure-stat to check the safety valve operation during the final steam check. I simply note the pressure at which the valve starts to leak with the machine gauge or I connect one for Europiccola. I clean the valve seat, replace or adjust the spring to get the correct operation pressure - about 2 bar.

Tip- if you have an older pressure-stat model with the ball bearing safety valve, replace it with the newer teflon insert. It will perform better and not leak till operation pressure. Give it time to settle down on the valve seat. Don't forget to replace the spring as well, it is different to the old type and applies the correct pressure to the insert

 Anti-vacuum valve

I have had some success with rebuilding the anti-vacuum/steam valve. I was beginning to dislike this device as I have had a few machines which have sticking (not shutting) or leaking valves (when shut). I have managed to get/make the parts consisting of an EPDM o ring, a silicone seal and a 2mm stainless circlip to refurbish the valve . Click on the photo