The Yoshitake KBFV-1S is a pneumatic butterfly valve designed with a stainless steel body and a double-eccentric structure. This construction provides excellent sealing performance and a long service life with minimal seat wear. The pneumatic actuator can be easily connected to accessories using NAMUR standard dimensions, making it suitable for automated control in systems handling steam, air, hot and cold water, oil, and other non-hazardous fluids.

Features

• Stainless steel body and ball for durability.
• Double-eccentric structure for minimal seat wear and excellent sealing.
• Double-acting pneumatic actuator with ISO5211 valve mounting and NAMUR accessory mounting.

Specifications

Valve Specifications

Specification	Details
Nominal Size	50-150A
Application Fluid	Steam, air, hot and cold water, oil, and other non-hazardous fluids
Material (Body, Cap, Ball)	Stainless steel
Material (Seat)	PTFE
Connection	Wafer (JIS 10K, ANSI 150lb, EN PN16)
Maximum Pressure & Temp	According to the Pressure-Temperature rating
Piping Orientation	Horizontal or Vertical (inverted horizontal is not allowed)

Pneumatic Actuator Specifications

Actuator Model	KA50, KA75, KA110, KA160, KA255
Operating Fluid	Air, nitrogen gas
Operating Pressure	0.4 MPa to 0.8 MPa
Ambient Temperature	-20 to +80°C
Operation	Double action
Operation Angle	90° ± 5°
Body Material	Aluminum alloy

Actuator Sizing

Valve Size	Actuator Model
50A, 65A	KA50
80A	KA75
100A	KA110
125A	KA160
150A	KA255

Output Torque (N·m)

Actuator	0.4 MPa	0.5 MPa	0.6 MPa	0.7 MPa	0.8 MPa
KA50	40	50	60	70	80
KA75	63	78	94	110	125
KA110	90	113	135	158	181
KA160	132	165	198	231	264
KA255	200	251	301	351	401

Operation Principle

Opening the Valve When the operating air is supplied into port A, the pistons move outward discharging air from port B, and the drive pinion rotates counterclockwise (0° to 90°). As a result, the valve opens.

Closing the Valve When the operating air is supplied into port B, the pistons move inward discharging air from port A, and the drive pinion rotates clockwise (90° to 0°). As a result, the valve closes.

Installation and Usage

Installation Recommendations

• Always install a strainer (80–100 mesh) on the inlet side of the product.
• It is recommended that a regulator is installed on the operating air piping for the actuator.
• Ensure that no excessive load, bending, or vibration is applied to the product.

Restrictions

• Do not install the actuator upside down.
• Do not use metal gaskets; use sheet gaskets when connecting the valve to pipes.
• Ensure that the regulator pressure is set to 0.8 MPa or lower.
• Avoid installing the product near pump outlets or downstream of elbows and reducers. If unavoidable, maintain a distance of at least 5 times the nominal diameter to prevent unbalanced flow forces.

High Temperature Hazard

For high-temperature fluids, do not touch the product directly with bare hands as there is a risk of severe burns. Always ensure the pressure inside the product and piping is at atmospheric pressure before maintenance.

Maintenance and Troubleshooting

The actuator is lubricated at the factory and does not require further lubrication. Regular inspections should be performed approximately once a year.

Troubleshooting Guide

Fault	Possible Cause	Countermeasure
External leak from the gland part	Nut is loose	Tighten nut. If the leak does not stop, replace the product.
Seat leakage	Damaged seat/disc or foreign object caught	Remove the foreign object or replace the product.
Actuator not operating	Operating torque is not enough or locked by foreign substances	Check if the operating air pressure is appropriate or clean the valve.
Stops at intermediate position	Valve is locked due to foreign substances stuck inside	Clean the valve.