Vacuum isolated transfer lines for bath cryostats

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1 for bath cryostats Last modified /09 Description The vacuum isolated transfer lines are used for transferring liquid helium. The vacuum isolated transfer lines can be manufactured with different diameters, depending on the required flow. The possible inner diameter depends on the maximum outer diameter of the vertical leg in the helium vessel or in the cryostat respectively. To minimize the loss of liquid helium on the whole transfer distance, the transfer lines are vacuum isolated and equipped with a high-efficient superisolation. Using the vacuum sluice on the evacuation valve, the transfer lines can be re-evacuated at any time. The safety valve provides protection of over-pressure in the vacuum area in case of a leak. The transfer lines are manufactured under constant testing, are verified in cold and warm state and evacuated with a HV-pumping station. Integrated adsorption materials guarantee a long lasting vacuum. Low helium loss Superisolated-vacuum High flow-rates Integrated vacuum safety-valve Re-evacuateable Completely made of stainless steel Thread for extension present < DN 3,6 semi flexible version (max. 800 mm length) > DN 5 flexible version Custom dimensions available for a small charge (please specify dimensions in case of an order) are manufactured in various standard designs but many different custom designs or dimension are possible, too. In special cases, the drives of the cold valves can also be aligned horizontally. We manufacture entire vacuum isolated transfer lines of larger nominal diameter (< DN0mm), even with radiation shields or exhaust gas cooled respectively, including the needed accessories and cold valves on customer proposal. Selection criteria Due to its own design, every transfer line is subject to physical constants regarding heat loss caused by radiation and conductance. The standard -versions of our transfer lines are an ideal compromise of useability and helium losses. Hence it is suggested to keep the planned custom designs concerning the length (especially the semiflexible parts), number of couplings, additional cold valves, etc. as close to our standard as possible. We would be glad to advise you in the design process. For the selection of custom dimensions, please refer to the following table showing the tube dimensions. Nominal inner diameter (mm) DN 3,6 DN DN 7,9 DN 9,6 minimum outer leg diameter (mm) 10 (9,5) (9,5)

2 for laboratory bath cryostats U-Type shape, with cold valve and evacuation-/safety valve for laboratory cryostats Order-No.: L-2038 with a coupling in the horizontal part are applied, where the transfer line cannot be inserted or drawn out because of e.g. low experimental or ceiling heights. In this case, the cryostat part of the transfer lines remains inside the cryostat after decoupling (slightly elevated). These transfer lines are available in rigid or semi flexible versions either with or without cold valve on the cryostat side of the transfer line (please provide customer dimensions in case of an order). U-Type, rigid shape, separated version (rigid), with cold valve and evacuation-/safety valve for laboratory cryostats 1 cold valve Order-No.: L cold valves Order-No.: L-2044 U-Type, semi-flexible shape, separated version (semiflexible), with cold valve and evacuation-/safety valve for laboratory cryostats 1 cold valve Order-No.: L cold valves Order-No.: L-2046 Last modified /09

3 for larger bath cryostats Description When using larger bath cryostats it is recommended to use transfer lines with a bigger nominal diameter to reduce the refill time. Their diameter is defined by the maximum possible outer diameter of the vertical part of the vessel of the cryostat respectively. These transfer lines are only manu-factured customer related, so many different dimensions or designs are possible. The vacuum isolated transfer lines are manufactured in rigid or semiflexible versions, in one or optionally more parts with couplings. Flexible length in relation to the expected height balance with a coupling in the horizontal part are applied for helium refill, where the transfer line cannot be inserted or drawn out because of e.g. low experimental or ceiling heights. In this case, the cryostat part of the transfer lines remains inside the cryostat after decoupling, slightly elevated and blindflanged on the coupling or in case of a cold valve closed. With experiments where the cryostat is adjusted with high precision, semi-flexible versions are preferred. The lateral positioning of the vessel and the coupling of the transfer line cinsiderably facilitates the refill procedure essentially. Last modified /09 For the automatic refill in connection with level controllers (see separate data sheet), the transfer lines can be equipped with a pneumatic cold valve and an electromagnetic precontrol valve. Princple drawing: automatic LHe-refill system

4 for bath cryostats U-Type, rigid shape, simple version with evacuation-/safety valve for laboratory cryostats Order-No.: L-2048 U-Type, semi-flexible shape, simple version with semiflexible part, evacuation-/ safety valve for laboratory cryostats Order-No.: L-2049 U-Type, semi-flexible shape, simple version with fullflexible part, evacuation-/safety valve for laboratory cryostats (flow rate L-2050 up to 20 l/h; L2930-C up to 60 l/h, p = 0,2 bar) A 1050 B 50 C F 800 DN Order-No. 3,6/6 L-2050 /6 Z-2930-C Last modified /09 U-Type with coupling valve shape, simple version with coupling valve (on the cryostat side), evacuation-/safety valve for laboratory cryostats. The valve seat is located inside the female coupling part, which is opened when the coupling is connected. Both parts of the transfer line are matched to each other, so the standard male couplings cannot be used. Order-No.: L-2049

5 für größere Badkryostate U-Type, rigid shape (rigid), with cold valve and evacuation-/safety valve DN (DN 7,6 and DN 9,6 as well as custom dimensions on request). (Flow rate ca. 50 p = 0,2 bar) Order-No.: L-2055 Table of dimesions (mm) A B C D E F DN Figure upper Order-No. L-2055 L-2057/1 L-2057/2 L-2057/3 U-Type, semi-flexible shape, with semi-flexible part with cold valve and evacuation-/safety valve DN (DN 7,6 and DN 9,6 as well as custom dimensions on request). (Flow rate ca. 50 l/h@ p = 0,2 bar) Order-No.: L-2057/1-3 Last modified /09

6 for larger bath cryostats U-Type, fullflexible shape, dividable version, vessel side with fullflexible part, with cold valve and evacuation-/safety valve DN (DN 7,6 and DN 9,6 and custom dimensions on request). (Flow rate ca. 50 p = 0,2 bar) Order-No.: L-2059/1-3 Table of dimensions (mm) A B C D E F 350 DN 7,6 Figure upper upper upper Order-No. L-2059/1 L-2059/2 L-2059/3 L-2061/1 L-2061/2 U-Type, fullflexible shape, like L-2059, cryostat side equipped with additonal cold valve and He-safety valve. DN (DN 7,6 and DN 9,6 as well as custom dimensions on request). (Flow rate ca. 50 l/h@ p = 0,2 bar) Order-No.: L-2061/1-2 Last modified /09

7 for larger bath cryostats Besides the common, manual driven cold valves, which are located in the angle area, there are also custom designs available. Automatic cold valves When an automated refill is necessary or a manual valve is not accessible, our tranfer lines can also be equipped with an automatic cold valve. Due to the force for tightening, the automatic cold valves consist of a valve rod with pneumatic piston and pressure spring. For opening the valve, the piston is pressurized through a 3/2 way control valve. All of the mentioned drives can be exchanged with manual dirves. The drive type II can also be equipped with a position switch for position acknowledgement. Technical data Drive I Drive II Working principle Pressurized air Control valve (3/2-Way) for L-2038, L-2043, L-2044, L-2045, L-2046 for L-2055, L-2057, L-2059, L-2061 spirng closing, pneum. opening 4-6 bar (oilfree) 24V / 220V/50Hz V / 24V (DC) Last modified /09 Bottom valves The bottom valve with drive is typically used at helium liquifiers where the liqiud helium is transferred from the larger vessels into smaller vessels. Since these transfer lines remain inserted into the tank, it is guaranteed that no air or moisture could leak in. The bottom valve without drive is also applicated here, however inside the tank. This means that the transfer lines is elevated slightly inside the quick lock after the filling process, which automatically closes the valve and avoids oscillations inside the tank. Both valves can be mounted on each transfer line for bath cryostats

8 for bath cryostats end pieces The sinter part serves as a sieve for any contaminations in the liquid cryogen and prevents ice to enter the transfer line. It can also be used as a phase separator on the cryostat side of the transfer line. To reduce the losses while filling, especially when using refill transfer lines on liquifiers or decanting plants, it is recommended to use an end part with lateral openings in the transfer line. Order-No.: WN-411-E Order-No.: WN-436-E Transfer line extensions are used for matching the length of different He-vessels. Moreover they are used for separations that are required to insert a line into a vessel due to low ceiling or experimental height. double-walled (not vacuum isolated) Diameter matched to the transfer line Completely sealed while introducing into the can Endpart with thread Note: Please remark type of transfer line, tube- and thread diameter in case of an order. Order-No.: Z-3653-E Last modified /09