Valve causes of malfunction

The valve is a mechanical device with flow control function

Malfunctions may occur due to various causes:

• corrosions
• deposits
• grooves
• cliques

This means that even with the valve closed, it is impossible to control the fluid: this causes leaks.

Leaks in sealing: consequences

• security issues
• lack of control
• poor efficiency

Which solution should we adopt?

Objective: to restore the functioning of the sealing seat, ensuring perfect closure.

Solution: intervene on the coupling between the valve shutter and the relative sealing seat.

Repair interventions of this type require specific equipment depending on the type of valve.

Restoring valves with flat sealing seats

Gate valves

Restoration of ball seat valves

Ball valves

Portable high-speed grinder lapping machine for flat seat valves

The EFCO HSL is a portable machine ideal for restoring valve seals. It is particularly suitable for grinding and lapping gate valve seals. However, it can also be used for other purposes requiring the restoration of flat surfaces.

The EFCO HSL is characterized by its high speed. This results in a time saving of approximately 90% compared to previous models. Its modularity makes it adaptable and versatile. The machine consists of an arm, to which the main gear is keyed. Connected to this is a rotating disc, which houses the various rotating discs that rotate at high speed.

Nuova Simat is the official EFCO distributor for Italy.

Technical pluses

The HSL is designed to redefine the standards for valve seat machining. Its exceptional results are due to its innovative simultaneous rotation system. The main disc rotates slowly, combined with the ultra-high-speed rotation of the smaller discs.

Grinding speed: up to 21 m/s (826.8 “/s) Material removal rate: up to 2 mm/h (0.08 “/h)

This high rotation speed shouldn't be interpreted as compromising the quality of the final result. This is possible thanks to two factors: the EFCO clamping system and the special coating of the rotating discs. They are coated with cubic boron nitride (CBN), which is particularly suitable for machining metallic materials.

The high hardness of CBN combined with the innovation of the HSL simultaneous rotation system, guarantee excellent sealing seat recovery in extremely short times.

As a portable lapping grinder, the ECFO HSL covers a working range from 125 [mm] to 600 [mm]. It is therefore available in two models which differ depending on the diameter of the sealing seat to be machined:

Stationary lapping machine for ball valve sealing parts

Efco has introduced a new lapping machine to the market for the simultaneous machining of ball and valve seat surfaces.

This machine is designed for finishing small and medium-sized balls. It is suitable for a wide variety of sealing seats and balls, such as floating balls, guided balls, etc., where shape and surface quality are particularly important.



Nuova Simat is the official EFCO distributor for Italy.

Structure and performance

Simultaneously lapping the seat and sealing rings is particularly advantageous: this ensures optimal valve sealing, ensuring precise surface contact between the ball and the sealing seats, without allowing even the slightest fluid passage.



This process significantly reduces processing times compared to manual lapping, as the parts are not machined individually, reducing assembly and disassembly times and the margin for error. This is essential where an excellent finish is required.

Another very important feature is the structure of the machine.

It is equipped with three rotation shafts, the speed of which is continuously controlled by a computerized system. The computerized system also features an integrated lubrication system for constant distribution of the lapping mixture needed to lubricate the workpieces.



As for the numbers, Rotago is able to work on small and medium sized ball valves and in detail:

• It can work with a range of balls with diameters from 50 mm to 300 mm | 2” – 11.8”.
• supported weight: up to approximately 100 kg

It is possible to adjust the rotation speed of the shafts:

• the main shaft rotates at a speed ranging from 3 to 60 RPM
• the two secondary shafts rotate at a speed ranging from 3 to 80 RPM

In order to be able to lap the entire surface of the sphere, Rotago is also equipped with an innovative pendulum mechanism which, by causing the shafts to oscillate as they rotate, allows the entire surface of the sphere to be easily worked:

• The pendulum speed varies from 3 to 30 RPM
• The eccentric stroke varies from 0 mm to 60 mm | 0” – 2.4”.

EFCO ROTAGO

• Simultaneous lapping of ball valve sealing parts
• Significant reduction in processing times compared to the manual lapping process
• Exact surface contact between ball and sealing seats
• Continuous and independent speed control for each motor
• Integrated measuring system: constant distribution of the lapping mixture
• Adjustable stroke
• Adjustable pressure control for ball-seal contact adjustment
• Drip tray for the lapping mixture used
• Tailgate equipped with protection switch
• Timer con shut-off automatic
• Ball diameter: Ø 50 mm – Ø 300 mm (2” – 11.8”)
• Maximum ball weight: approximately 100 kg
• Main shaft speed (ball): 3 – 60 RPM
• Secondary shaft speed (seal seats): 3 – 80 RPM
• Pendulum mechanism speed: 3 – 30 RPM
• Pendulum (eccentric) travel: 0 mm – 60 mm (0” – 2.4”).

Nuova Simat is the official EFCO distributor for Italy.

It has been operating in the industrial maintenance and assembly sector since 1989. It is UNI EN ISO 9001:2008 certified for its Quality Management System. Customer-oriented, it offers targeted solutions to construction site issues.

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References Nuova Simat