The Yoshitake DD-3 is a direct acting solenoid valve featuring a stainless steel body and trim for outstanding corrosion resistance. It is designed for use with air, cold and hot water, and various gases (N2, CO2, Ar) as well as oil. The valve operates as normally closed and supports vertical or horizontal installation.

Features

1. Superior corrosion resistance with stainless-steel-made trim parts.
2. Vertical or horizontal installation is possible.
3. Equipped with coil of AC 110/220V selective and common for 50 Hz/60 Hz.
4. DD-3-8N can be used as a pilot solenoid valve for constant water level valve up to 50A.

Specifications

Model	DD-2, DD-2-8	DD-3, DD-3-8	DD-3-8N
Application	Steam, Cold/hot water, Air, N2, CO2 (dry), Ar, Oil	Cold/hot water, Air, N2, CO2 (dry), Ar, Oil	Cold/hot water, Air, N2, CO2 (dry), Ar, Oil
Fluid Viscosity	20 cSt or less	20 cSt or less	20 cSt or less
Working Pressure	0-0.15 MPa (DD-2) 0-0.8 MPa (DD-2-8)	0-0.15 MPa (DD-3) 0-0.8 MPa (DD-3-8)	0-0.8 MPa
Orifice	φ9.5 mm (DD-2) φ4.0 mm (DD-2-8)	φ9.5 mm (DD-3) φ4.0 mm (DD-3-8)	φ4.0 mm
Cv Value	1.7 (DD-2) 0.55 (DD-2-8)	1.7 (DD-3) 0.55 (DD-3-8)	0.55
Allowable Valve Seat Leakage	50 mL/min under standard conditions	No leakage (visually)	No leakage (visually)
Max. Temperature	175°C	100°C	90°C
Operation	Normally closed	Normally closed	Normally closed
Body / Plunger Material	Stainless steel (SCS14A) / Stainless steel	Stainless steel (SCS14A) / Stainless steel	Stainless steel (SCS14A) / Stainless steel
Valve Disc Material	PTFE	FKM	FKM
Connection	JIS Rc screwed	JIS Rc screwed	JIS Rc screwed

INFO

DD-3-8N is approved by the Japan Water Works Association (JWWA).

Coil Specifications

Rated Voltage	AC 100/200 V selective type	AC 110/220 V selective type
Frequency	50/60 Hz common	50/60 Hz common
Allowable Fluctuation	Rated voltage ±10%	Rated voltage ±10%
Rated Current	0.42 / 0.21 A	0.38 / 0.19 A
Starting Current	1.10 / 0.55 A	1.00 / 0.50 A
Insulation Class	Class H	Class H
Protective Structure	Dust tight, Splash proof	Dust tight, Splash proof
Ingress Protection	IP64 (JIS C0920)	IP64 (JIS C0920)
Insulation Resistance	50 MΩ and more (500V megger)	50 MΩ and more (500V megger)

(Coil equipped with a terminal box is also available)

Dimensions and Weights

Nominal Size	d	L (mm)	H (mm)	H1 (mm)	Weight (kg)
10A	Rc 3/8	55	85.5	12	0.66
15A	Rc 1/2	60	87.5	13	0.69
20A	Rc 3/4	65	91	16.5	0.74

Operation

• Opening operation: When the coil is supplied with power, the plunger is pulled up and extends the spring upwardly, opening the valve.
• Closing operation: When the coil is not supplied with power, the plunger drops down by its own empty weight and the spring load, closing the valve.

Installation and Piping

Warning

• Electric wiring work must be performed by a professional.
• The product cannot be used as an emergency shutoff valve. If the product is applied to a system that needs safety measures, install other equipment besides the product.
• The product is not explosion-proof. Do not use it in an area where explosive gases accumulate.
• Connect the cables only after confirming that no power is supplied.

Caution

• Vertical or horizontal installation is possible, however, do not install it upside-down.
• Match the fluid flow direction with the inlet and outlet of the product.
• Make sure to connect a strainer (80-100 mesh) to the inlet of the product.
• Do not apply insulation to the solenoid coil. Doing so may cause abnormal operation.
• When the product is used in a facility which cannot stop operating, install a bypass line with a bypass stop valve.

Piping Example:

Wiring Method

1. Wiring differs according to voltage (AC 100 V or 200 V). Wire the coil according to the instruction on the label.
2. Use electric wires which have a core of 0.75 mm² or more.
3. Use a fuse (3A) to protect the electric circuit.

Disassembly and Reassembly

WARNING

Confirm that no power is supplied before disassembling. Completely discharge the pressure inside the product and cool it down before touching.