BARBIERI RUBBER specialises in the design and manufacture of protective bellows and boots for hydraulic valve and hydraulic distributor levers. Forty-five years’ experience in the hydraulics sector has enabled us to perfect various rubber mixes that are resistant to hydraulic fluid, and at the same time resistant to atmospheric agents and direct sunlight. Thanks to these mixes there is no problem fitting dust boots on hydraulic distributor levers in closed cabins, even when they are exposed to direct sunlight. The average life of the boot fitted on a hydraulic valve does not determine the average life of the valve itself, but after breakage of the boot any dust, dirt and water that may filter into the body of the valve will cause it to deteriorate rapidly. Careful design and laboratory testing makes it possible to achieve standards of quality that were unimaginable just a few years ago: by selecting the most suitable polymer base, formulating the mixes using tried and tested recipes and designing the rubber protection carefully, it is possible to achieve a perfect seal on the lever, making it resistant to oil and grease and also to ensure an average working life that is more than adequate even in geographical areas with extremely hot or cold climates.
Another significant point is the aesthetic effect that a well-designed boot shaped to fit the lever can give to a hydraulic valve or distributor, particularly if the boot is capable of retaining its colour, surface finish and flexibility for a long period of time.
In the hydraulic pumps sector, Barbieri specialises in the design and manufacture of rubber seals, rubber membranes and anti-seepage gaskets. The mixes tested in the field and in the laboratory during the company’s 45 years activity in this sector mean that it is now possible to achieve excellent seal results even at high pressures, and prevent seepage even without the aid of additional rigid components. Barbieri’s patented technology allows “flash-free” moulding, which means a considerable improvement in seal-in rubber components working inside hydraulic pumps.
Constant contact with hydraulic fluid obviously requires the use of NBR-based mixes, but high pressures combined with relatively high temperatures, possible friction and the need to maintain a perfect seal often make it necessary to turn towards much more high-performance mixes or mixes that are designed and tested specifically for the pump in question.
High temperatures and the forces at work internally in the rubber seal or membrane result in an exponential reduction in the pump’s average working life. From this point of view, designing with the co-operation of the customer’s technical department is of fundamental importance, and it is frequently possible to reduce breaking points and the forces at work inside the material considerably, whilst maintaining the same results in terms of pump seal and operation. Lobe, gear, blade, screw and piston pumps all require particular care when designing and moulding rubber components, as the mechanical stresses, temperatures and reliability required to produce a quality pump make it necessary to create oil seals using dedicated materials and with dedicated shapes. The compression set is also a characteristic that must not be underestimated, as in the case of a rubber pump body or when carrying out maintenance on the seals it is essential that the geometry returns to its original dimensions even if it is twisted or bent and subject to a number of changes in temperature.
Barbieri Rubber also produces a series of rubber accessories for hydraulic valves and distributors, such as actuator buttons using rubber-metal co-moulding technology, valve or solenoid valve guards, connector covers and simple dust guards that snap onto the body of the valve or distributor, obviously all made of oilproof rubber that is also resistant to ozone.
For certain particularly heavy-duty applications, or when it is necessary to achieve high levels of reliability, such as power stations, planes or aerospace, railway applications, safety devices, safety valves, deviators, maximum pressure, filler and proportional valves, mixes that are always oilproof, but are also long-lasting and resistant to extremely acid or alkaline substances are used.
Design and manufacture of seals for hydraulic cylinders without doubt requires particular care, given the extremely high pressures involved and the continuous friction with metal components in the cylinder. In order to increase the average life of the hydraulic cylinder considerably, no dust, small particles or other abrasive elements must be deposited on the cylinder shaft, as they might damage the chrome plating or cut into the rubber seal. Barbieri Rubber is a leader in the design and manufacture of bellows to protect hydraulic cylinders from all external agents.
The use of filters means that the bellows fitted on the cylinder can “breathe” whilst keeping the air inside it perfectly clean, so that the cylinder rod is always in contact with filtered air even in particularly dusty environments. Automatic cleaning of the filter as the piston closes is normally sufficient to keep it free from any blockages that would prevent normal operation. The mix used is obviously resistant to oil, but it is also resistant to ozone and other atmospheric agents. However, special mixes are necessary in the case of high temperatures, or when there is the need for a particularly long working life and high levels of reliability.
Barbieri Rubber also produces a series of rubber accessories for hydraulic pumps and distributors, such as pump membranes, guide bearings and rubber lobes using rubber-metal co-moulding technology, rubber pump bodies comprising membrane or helical screw, protections for pump components, connector covers and simple dust guards that snap onto the body of the pump or tap. For certain particularly heavy-duty applications, or when it is necessary to achieve high levels of reliability, such as marine propellers, planes or aerospace applications, pumps with a high head, etc… mixes that are always resistant to the fluid with which the item is to be in contact, but those that are also long-lasting and resistant to extremely acid or alkaline substances are used.