The shaft seal is a double-acting bidirectional mechanical seal made to DIN standards.It can be applied to vessels made to DIN 28136 of steel or stainless steel with mounting flanges according to DIN 28141 fitting shaft ends made according to DIN 28154.The shaft seal is designed with a total of four seals rings,with two indentical seal ring pairs arranged back-to-back.Product and atmospheric side seal ring pairs are hydraulically balanced via flexible secondary seals.This ensures that the position of the seal rings remains unchanged also if the pressure acting on the seal is reversed.Since the flexible secondary seal are only mechanically loaded by the force of the springs acting on the seal ring,their elasticity is retained.This principle allows high radial deflection of the shaft without any negative influence on the sealing gap and consequently on the sealing effect.
The mechanical seal is the most commonly applied shaft seal for agitators worldwide.Due to its modular design it can be modified to suit various needs.By having product wetted parts that are small in size,materials such as Titanium,Hastelloy or even glass-lined parts can be used economically.
Extremely robust and distortion resistant seal rings ensure almost zero-leakage even under the roughest conditions.Special spring designs ensure uniform pre-tensioned conditions even in cases of strong agitator shaft deflection.
In most cases the seal liquid chamber is pressurized to a pressure level which lies above the vessel pressure.(This is done either by a pressure overlay or by use of the SUNKAIER pressure compensator). The achieved pressure gradient eunsures a high degree of operational safety for applications up to 40 bar even using the standard version of the seal.
The main areas of application are:
Chemical industry
Hydrometallurgy
Pharmacy
Biotechnology