Sliding Gate Valves

The sliding gate seat is made up of two primary parts: a movable disc and stationary plate with multiple orifices. Together, this seat set achieves levels of performance, reliability and accuracy that are hard to find in other designs.

Quiet Operation

Compared to conventional globe and cage designs, the sliding gate seat generates between 5-10dB less noise. You won’t find a premium price adder for “low-noise trim”. The sliding gate valve is inherently quieter than other types of valves because:

• The disc and plate remain in constant contact, eliminating the chatter found in globe-style designs
• The straight-through flow passage minimizes turbulence found in globe and rotary designs, a primary cause of valve noise
• The multiple orifices in the plate and disc divide the flow into smaller flow streams resulting in less noise

Size and Weight

As the line size increases, so too does the size and weight of the valve. Because of the short stroke length, a sliding gate valve is typically smaller and lighter weight than a globe/cage style valve. For the Mark 75 Series control valve, the shipping size, weight, packing waste and costs decrease dramatically due to the wafer style design.

Reduced Turbulence

The tortuous flow path of a globe style design creates greater turbulence, noise and wear – reducing seat life and compromising control performance. When used in applications where flashing or cavitating occurs, damage to the valve body is common – and is mitigated only through expensive material upgrades or elaborate trim configurations.

A rotary control valve has similar wear issues due to turbulence. When throttling, the control member of a rotary control valve will direct the flow to the sealing area of the seat, causing premature seat leakage.

In contrast, the multi-orifice straight through flow path of the sliding gate valve reduces turbulence and leads to quieter operation, reduced wear, longer seat life and better control.

For example, when combined with the ultra-compact wafer body design of the Mark 75 Series, erosion of the seats and valve body is virtually eliminated – resulting in dramatic cost savings.

Straight-Through Flow

The seat set is perpendicular to the flow, unlike the traditional globe style design. With straight through flow, the turbulence is reduced and superior trim life is achieved.

The sliding gate design provides exceptional flow control since the flow works with the seat and not against it. In a typical globe style design, the flow goes underneath the plug, working against the plug. With the sliding gate, the flow pushes the disc against the plate, helping to hold the desired setpoint. This also enables the disc and plate to lap and clean themselves as the valve modulates. The sliding gate design “wears in” instead of wearing out.