SensoGate WA 131

Universal, pneumatically operated retractable fitting with modular design for basic control

Based on the proven SensoGate® modular design principle, the new WA 131 retractable fitting is ideal for applications which do not require completely automated control but which still require superior SensoGate ® technology.


Variable and reasonably priced
The development of Ceramat® WA150 fitted with a ceramic gasket for processes involving extreme applications and the SensoGate® flagship WA 130 (H) complete Knick's retractable fitting program, each of them equipped to provide the right functionality for individual applications. SensoGate® WA 131 is ideal for automatic or semi-automatic connections to commercially available or customer-developed control units.
The new, low-price SensoGate® WA 131 models offer many advan­tages for applications which require that the sensor can be easily removed on site either for maintenance pur­poses or to be replaced. This is also true wherever cleaning is necessary and this can be done simply on site by hand or via remote control – even in hazardous locations. All SensoGate® WA 131 fittings are available ­explosion-protected. The design is scalable to meet requirements; when placing an order, customers simply state the types of connections and functions they need. Every design permits the sensor to be manually serviced or replaced. This can easily be done under process pressures as great as 10 bars. The sensor lock-gate supplied by Knick is thus designed precisely for your ­special needs; optionally either with or without limit switches, with or without a rinsing chamber inlet. Manual or pneumatic with simple snap-in connections for the control air. For the first time there is also a low-cost variant with the process-wetted parts made of PP.For example, if at some later point another media connection is necessary, this can be very easily arranged by the simple replacement of the appropriate module. A switch from metal to ­plastic or a switch to electrodes with a store of liquid electrolyte is possible – one big advantage of the SensoGate® modular design.The patented lock-gate function, i.e., the reliable shut-off to the process even during movement, is always ­active. This also applies to the hygienic version, which is a unique design ­feature in the world market for retractable fittings


Easiest maintenance
Compared to other devices, the ­manual sensor lock-gate, sophisticated down to the smallest detail, cuts the time needed to replace wearing parts by as much as 70%. This is also helped by our special installation tools. For example, the O-rings can be completely replaced in just a few minutes; the gaskets are easily accessible and can be exchanged very quickly. Design innovations also ensure that the O-rings have an extremely long service life.


Materials
Today, conventional retractable fittings are available in the widest range of materials: PP, PEEK, PVC, steel, Hastelloy, titanium etc. Plastics frequently provide advantages to resist chemical stresses, but these have been out-weighed to some extent by the disadvantages of the designs. They are thermally instable, tend to swell and therefore do not have enough dimensional stability. In particular, immersion tubes made of plastic are greatly limited in terms of their application, cannot move after swelling and often malfunction at an early stage.
By contrast, the plastic versions of the SensoGate® are reinforced with carbon fiber. In addition to the chemical resistance of the reinforced PEEK, PVDF or PP, the calibration chamber and the immersion tube retain their shape even when exposed to higher temperatures. The immersion tubes made of carbon-fiber-reinforced plastic are injection-molded rather than cut so as to avoid tool marks. The advantage of this method is that all the fibers remain covered by the surface. Cutting such fiber-reinforced plastics on a lathe would expose fibers and the resulting surface would be too rough for the O-rings to slide over.


Attractive in every way
The result of Knick’s injection-molding is a straight pipe with a cohesive surface of excellent quality. The direct benefit for the customer is the minimal O-ring wear and the correspondingly long service life of the gaskets. At the same time these materials can also be used at a great cost advantage where until now serious chemical stress combined with high pressures and temperatures have required extremely expensive materials such as Hastelloy. In addition to the price there is another enormous advantage: The fiber-reinforced plastics used by Knick have thermal expansion characteristics similar to those of steel. There are no longer any pressure restrictions on the permissible temperature range, due to the division into pressurized components made of steel and process-wetted materials made of carbon-fiber-reinforced plastic. The pressure stability is the same at room temperature as it is at 120 °C / 140 °C.


Explosion protection
Another benefit is the conductivity of plastic carbon-fiber-reinforced components especially for the use of SensoGate® in hazardous areas. The sensor basket made of conductive plastic prevents the electrodes from building up electrostatic charge and, in turn, distorting the measurements.
The SensoGate® is approved for use in hazardous areas in accordance with qualifications II 1 GD c II.


Process adaptation
SensoGate® retractable fittings can be adapted to various processes with a steel flange 1.4571 DN 32 to DN 100, dairy pipe screw joint DN 50 to DN 100, !/2; to 3; ANSI 316 flange and 25-mm Ingold socket or hygienic process connection. Other special ­adaptations – such as for flow cells – are possible.


Hygienic and safe
The hygienic ­SensoGate® WA 131 H is EHEDG ­certified. Unlike other conventional fittings on the market, both the process side and the rinsing chamber are EHEDG certified. This means that its suitability for unrestricted use in pharmaceutical and food applications has been attested. This also allows validation in FDA-­regulated production processes. The only part of the immersion tube which comes in contact with the process is that part which was previously sterilized in the rinsing chamber. In addition to sterility, it is also vital that the tube can be cleaned. The SensoGate® fittings have turned the concept of a mandatory rinsing into a reality; an integrated flow body directs the hot steam or rinsing liquid across all the surfaces to the foremost gasket. Another variant allows the process flange in the SensoGate® to be moved which, in turn, enables greater immersion depth. The hygienic SensoGate® is the only fitting in the market to offer hygienic design plus a genuine gate function. At no time – not even during probe movement – is there any contact ­between the process and the (possibly unhygienic) surroundings.


Unique variety
The variety of the freely combinable materials, modularity and the quality of SensoGate® retractable fittings is unique worldwide. There is not even anything approaching the degree of flexibility which this modular system for sensor lock-gates provides in the way materials and functionality can be so freely selected and interchanged: Plastic (PEEK, PVDF, PP) or metal (stainless steel, Hastelloy), designs for use with chemicals or ­hygienic applications, manual or ­pneumatic – optionally for liquid or solid polymer electrolyte sensors, long or short immersion depths. The fitting adapts perfectly to the application and can even be adapted later to changed conditions.


Made in Germany
Bucking the trend to outsource production, the fittings are manufactured, assembled and tested at Knick's own Berlin headquarters. This reflects our belief in keeping our core competences in-house and in creating highly specialized areas of production which cannot be expected of suppliers on contract with such a consistent level of quality and flexibility. These production conductions also enable Knick to respond to orders without delay.Each component is engraved with its own number directly at the machine. This documents precisely and in detail which customer gets which components. This unique traceability permits, for ­example, a test certificate to be supplied for each individual fitting on request, even years later.