Modular Bellows

A modular system for countless solutions

✔ Combine different elements to create multiple configurations

✔ The length can be extended by connecting the bellows via the joint

✔ Adaptable to multiple applications, with holes in the collars of the required diameter

✔ Fast delivery

✔ No mold costs

✔ Easy replacement of modules

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Description

Modular Rubber Bellows — Plug-and-Play Kit, Always In Stock

Barbieri Rubber modular bellows are cylindrical protective bellows built around a kit system: bellows body, end collars and joints fit together with no glue, no special tooling and no dedicated equipment. They are the simplest and most economical way to protect a rod, a lead screw, a pneumatic or hydraulic cylinder, a linear actuator. Eight size classes, three standard compounds (NBR, EPDM, food-grade orange silicone RAL 2004), ready to ship from stock.

 

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Watch the video below to see how easy it is to use the modular bellow

Why modular: no mold, no tooling cost

The difference compared to a traditional bellows is sharp. The modular bellows requires no dedicated mold: the kit components are standard catalog items, already molded and ready to assemble. No tooling cost, no minimum batch tied to mold amortization, no production lead time. The system is designed to be used as it is, autonomously by the customer, and is therefore not offered in a custom-design version: its purpose is exactly to solve a mechanical-protection problem right now with what is already in stock.

How the kit is built

The Barbieri Rubber modular system is made of five item codes, identified by the prefix BLW followed by class and compound. The bellows (BLW B) is the extendable body — the accordion tube absorbing the stroke. The collars (BLW C) are the two end elements that close the bellows onto the machine flanges: each collar has a centered pre-hole (10 mm on classes 60–120, 30 mm on class 135) that the customer drills to the desired diameter, recommended 1.5–2 mm smaller than the flange to obtain a perfect elastic grip. The joint (BLW J) is optional and connects two or more bellows for longer assemblies. The plastic disc (BLW D) snaps into the joint and supports the bellows weight when several modules are connected horizontally. The filter (BLW F) is fitted at one end to keep internal air clean when the bellows works on long strokes.

Order code

The coding is modular and self-explanatory: BLW + component letter + class + compound letter. Examples: BLW B 106 R = bellows class 106 in NBR; BLW C 120 E = collar class 120 in EPDM; BLW J 83 S = joint class 83 in orange silicone; BLW D 135 = plastic disc for joint class 135; BLW F = filter. For a complete medium-length protection one bellows and two collars in the same class and compound are enough; for longer assemblies, modules and joints are added.

Industries served

The modular bellows is the natural choice for machine shops, machine builders, industrial maintenance and any case where a fast and cost-effective solution is needed: protection of rods and cylinders in oil hydraulics and pneumatics, lead screws and linear actuators on machine tools, outdoor actuators on photovoltaic plants (in EPDM), food and pharmaceutical applications (in orange silicone, food-contact compliant), telescopic joints, moving parts exposed to dust, swarf, oil or water splashes.

Frequently asked questions

How are class and length selected?

Start from the diameter of the flange the collar will grip and pick the class whose pre-hole, drilled 1.5–2 mm smaller than the flange diameter, gives the correct elastic grip. For the length, compare the stroke to be protected with values L (closed/open) in the table: if a single class is not enough, joints and modules are added. In case of doubt, send flange dimension, minimum and maximum stroke and working direction (vertical or horizontal).

Are special tools or skills needed for assembly?

No. Bellows, collars and joints assemble by hand snap-fit. The only required operation on the collars is drilling the pre-hole to the flange diameter, which can be done with a normal drill press. For long horizontal assemblies, plastic discs BLW D should be inserted in the joints to prevent body sagging.

Which compound to choose between NBR, EPDM and silicone?

NBR (black) for environments with mineral oils, greases and hydrocarbons: standard choice for oil hydraulics, pneumatics and machine shops. EPDM (black) when the bellows works outdoor or is exposed to UV, ozone and weather, typical of photovoltaic and outdoor applications; not resistant to mineral oils. Orange silicone RAL 2004 when high temperatures (up to +200 °C) or food-contact compliance are required: food & beverage, pharmaceutical, ovens, clean environments.

Are they really ready to ship?

Yes. All standard combinations of class + compound listed in the table are normally available from stock. For large quantities or less common configurations (for example 135 medium/long in NBR) it is advisable to confirm availability when issuing the request for quotation.

Additional information

Application Areas

When dirt, grit, metal chips, water, and other contaminants are deposited on exposed piston rods of hydraulic or pneumatic cylinders, or on screws and rods of jacks and electric actuators, these contaminants drastically reduce the lifespan of sealing rings, causing leaks and damaging the device irreversibly. Moreover, contaminants may work their way into the hydraulic fluid and cause problems throughout the system.

Under these conditions, installing a protection bellow can make a huge difference in terms of durability. The problem lies in the availability of a bellow having collars with correct dimensions, closed length and stroke. Barbieri Rubber’s modular system can solve all these problems and is the perfect solution within their range of dimensions.

BARBIERI RUBBER holds the patent of the MODULAR BELLOW, which can be adapted to the dimensions of the flange on which it must be installed (from 10 mm to 118 mm).
Standard materials

(always in stock):
NBR:

Oil resistant (black) Resistant to oil and grease. Protected against sunrays for outdoor applications. Excellent elasticity and durability.
EPDM:

(black) Resistant to sun and weather agents for long-lasting outdoor applications. Not resistant to oils and grease.
SILICONE:

(orange, RAL 2004) Food-grade, resistant to a continuous heat of up to 200 °C. Top quality, elasticity and durability. Fairly good resistance to oils and grease.
Installation

A hole of the required size and shape is drilled into the collars to fit them on the machinery.

The collars are made of the same elastic rubber as the bellow. Therefore, the entire diameter must be smaller than the diameter on which they will be installed (fitted).

We recommend applying a hole 5% smaller than the diameter on which they will be fitted.

Then, another hole must be drilled to allow for the passage of air.

The axial movement causes a variation in the internal volume.

Therefore, this hole is important because the air must enter and exit the bellow during the movement cycles. Slow cycles (exceeding 5 seconds) require one air passage hole, while faster cycles require two or more holes.

Installation
A filter allows the bellow to retain clean air and leave dust and solid contaminants, whose dimensions are larger than the filter’s mesh, outside.

For vertical or inclined installations (outdoor applications), the application of the filter to the lower flange protects the rod against liquids and rain and also allows the condensation (if any) inside the system to drain.
Production

Barbieri Rubber manufactures all modular bellow components through injection molding and vulcanization (The chemical reaction typical of the production of technical rubber products). The same reaction occurs during the production of vehicle tires.
Other rubber bellows models

For applications that require dimensions other than those covered by the modular bellows, see standard bellows. In the event a special bellows is required, Barbieri Rubber offers complete custom design, engineering, and manufacturing services based on 50 years of experience.

Based on your requirements in terms of shape, movement, and environment, we will propose the best material for a wide range of extreme applications (high and low temperatures, presence of oils and solvents, acids, aggressive chemicals and other fluids). We will also study materials and shapes for particular conditions, such as abrasion, high operation frequency, solar radiation, presence of ozone, oxygen, or dust and grit.

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