What is the difference between the MY and the MY-1S series?

The MY is the base model of the series — compact, with ratios from 24:1 to 68:1, covering 300–8,500 Nm for small and medium-sized valves. The MY-1S series adds a spur gear stage to the same worm gear platform, extending torque to 170,000 Nm with much higher ratios for large valves.

Which valves can the MY series be mounted on?

Butterfly, ball, plug and rotary ball valves with 90° travel, plus three-way ball valves and other three-way valves that require a full-rotation multi-turn worm gearbox to switch between flow paths. All mounting flanges follow ISO 5211, and the stem bore and mounting height comply with international standards, so the gearbox assembles directly onto the valve.

How much effort does manual operation require?

Input torque ranges from just 41 to 425 N·m across the nine models. Matched with the appropriate handwheel diameter, every size can be operated smoothly by hand.

Can the MY gearbox be used outdoors or in submerged conditions?

Standard protection is IP67. For special environments such as flooding-prone or buried installations, IP68 and immersion protection are available on request.

MY Worm Valve Gearbox, 300–8,500 Nm

Name: MY Series Manual Part-turn or Multi-turn Worm Valve Gearbox
Brand: YOYAGE

Manual

Product Overview

MY Worm Gear Operator

The MY series is YOYAGE's base manual worm gearbox — a part-turn or multi-turn worm gear operator for butterfly, ball, plug and rotary ball valves, plus three-way ball valves and other three-way valves that need full-rotation multi-turn operation. Adding a spur gear stage creates the MY-1S for higher torque and ratio; replacing the handwheel input with an actuator flange creates the MY-D for electric operation. The precise-cast housing comes in multiple materials to suit different media and working conditions, while the self-locking worm gear pair and tapered roller bearings ensure flexible and efficient operation with low handwheel input torque. ISO 5211 mounting flange; IP67 as standard, IP68 optional for special environments. Manufactured in compliance with CE and ISO 9001 standards.

Standard Type: Part-turn or Multi-turn
Gear Type: Worm Gear
Ratio: 24:1–68:1
Torque: 300–8,500 Nm
Protection: IP67 (IP68 optional)
Housing Material: Ductile Iron, WCB (common)

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Product Features

Self-locking worm gear set prevents valve back-driving
Heat-treated worm with high hardness and wear resistance
Precision-ground gears for smooth rotation and high efficiency
High-strength input shaft with protective plating
C3/C5 coating system for surface protection
Reliable bearing support for stable operation
Grease-filled lubrication for extended service life
NBR seals for enhanced sealing performance
Rigorous torque and low-temperature testing

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Custom Solutions

Housing materials: Ductile iron, WCB, CF8/CF8M, LCC, LCB, LC1
Full-bronze or bronze-rimmed worm wheel
Part-turn or multi-turn valve gearbox
Gear ratio customization on request
Handwheel & chainwheel size customization
Worm gear hubs customization (Valve stem)
MSS flange standard or custom connections
Handwheel locking device
Low-temperature service down to -59°C
C5 coating system
IP68 protection option

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Technical Parameters & Dimensions

Read our selection guide: How to Choose a Valve Gearbox for Industrial Valve Applications

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Dimension Drawing D · D0 · PCD · D1×h · Φd · Keyway · H1 · H2 · K · K1 · K2 · K3 · L · L1 · ΦPD · b · L0 · M

YOYAGE MY part-turn or multi-turn manual worm valve gearbox dimension drawing with ISO 5211 mounting flange details

Technical Parameters & Connection Size

Model	Ratio	Max TorqueN·m	Max Torquekgf·m	Input TorqueN·m	FlangeISO 5211	Flange Dia.D	Bolt Circle Dia.PCD D0	Bolt SpecN-H-DP	ConvexD1×h	Max Stem Dia.Φd	Keyway
MY-000	24:1	300	31	41	F07	90	70	4-M8-15	55×3	20	6×6
MY-00	33:1	500	51	50	F10	125	102	4-M10-15	70×3	30	8×7
MY-0	39:1	980	100	85	F12	150	125	4-M12-18	85×3	38	10×8
MY-1	46:1	1,600	143	115	F14	175	140	4-M16-24	100×4	45	14×9
MY-2	49:1	2,700	255	185	F16	210	165	4-M20-30	130×5	55	16×10
MY-3	53:1	4,200	478	255	(F20)	250	205	8-M16-24	140×5	65	20×12
MY-4	60:1	5,600	617	315	F25	300	254	8-M16-24	200×5	80	22×14
MY-5	62:1	7,000	714	380	F30	350	298	8-M20-27	230×5	105	28×16
MY-6	68:1	8,500	867	425	F35	415	356	8-M30-45	260×5	115	32×18

Appearance & Handwheel Size (mm)

Model	H1	H2	K	K1	K2	K3	L	L1	ΦPD	bKey	L0	MHandwheel
MY-000	41	124	75	40	-	195	65	105	15	5	32	250
MY-00	55	151	70	43	42	200	70	110	15	5	32	250
MY-0	66	208	89	51	47	224.5	83	134.5	21	6	36	300
MY-1	75	230	89	52	58	237.5	92	147.5	21	6	36	350
MY-2	92	270	108	63	62	279	113	189	28	8	46	450
MY-3	111	303	110	61	60	307	125	207	28	8	46	500
MY-4	145	373	140	85	100	337	160	237	28	8	46	600
MY-5	160	420	140	87	102	498	197	298	45	12	61	650
MY-6	200	495	179	110	112	532	230	332	45	12	61	700

Need MY Series Selection Support?

Send your valve type, size, and torque requirements to the YOYAGE team for model selection and quotation.

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MY Series Manual Part-turn or Multi-turn Worm Valve Gearbox