Miyawaki S31N Thermodynamic Disc Steam Traps

Manufacturer: MIYAWAKI Inc.
Model: S31N

Features

Compact and cost effective design
It has a space saving, simple mechanism with very few moving components.

Easy maintenance
The minimum of moving parts and an easy in-line access ensures easy and fast maintenance.

Special design against steam locking
To avoid cases of steam locking, Miyawaki offers special models to handle steam locking.
(S31N-G/S31NF-G, S31N-2/S31NF-2)

Flexible installation
This product can be installed either horizontally or vertically.

Auto blow off and air vent

Thanks to a bimetal ring, the trap smoothly discharges initial air and cold condensate. (Auto blow-off mechanism)

Typical applications

Suitable for steam main lines, small steam equipment, and other such applications.

Dimensions/Weight

Screwed

½”・¾”・1”

1 ¼”・1 ½”・2”

Size	Dimensions (mm)				Dimensions (in)				Weight
	L	H1	H2	W	L	H1	H2	W	(kg)	(lb)
½”	90	55	65	60	3.5	2.2	2.6	2.4	1,1	2.4
¾”		60				2.4			1,2	2.6
1”	95				3.7				1,3	2.9
1 ¼”	180	104	100	106	7.1	4.1	3.9	4.2	8,0	17.6
1 ½”									8,7	19.2
2”		111				4.4			9,3	20.5

Flanged

½”・¾”・1”

1 ¼”・1 ½”・2”

Size	Dimensions (mm)				Dimensions (in)				Weight
	L	H1	H2	W	L	H1	H2	W	(kg)	(lb)
½”	140	55	65	60	5.5	2.2	2.6	2.4	2,5	5.5
¾”	150	60			5.9	2.4			3,0	6.6
1”	160				6.3				4,2	9.2
1 ¼”	240	104	100	106	9.5	4.1	3.9	4.2	12,0	26.4
1 ½”									13,5	29.8
2”									14,5	32.0

Specifications

Model	Connection		Max. operating pressure		Max. operating pressure differential		Max. operating temperature		Body material
	Type	Size	PMO (MPa)	PMO (psig)	⊿PMX (MPa)	⊿PMX (psig)	TMO (℃)	TMO (℉)
S31N	Screwed Rc,NPT	½”	1,6	230	1,6	230	220	428	Ductile cast iron FCD450
		¾”
		1”
		1 ¼”							Cast iron FC250
		1 ½”
		2”
S31NF	Flanged FF,RF*	½”							Ductile cast iron FCD450
		¾”
		1”
		1 ¼”							Cast iron FC250
		1 ½”
		2”

*Available flange standards: ASME/JPI 150lb, 300lb, DIN PN16, JIS 10K, 16K, 20K. ASME/JPI 300lb not available for size 2”.

Maximum allowable pressure (PMA): 1,6MPa (230psig)　 PMA is the pressure that can be tolerated by pressure-resistant parts (body).
Maximum allowable temperature (TMA): 220℃ (428℉)　 TMA is the temperature that can be tolerated by pressure-resistant parts (body).
Min. operating pressure differential (⊿PMN): 0,03MPa (4.4psig)　⊿PMN is the minimum operating pressure differential between the trap inlet and outlet.

*Special design models against steam locking are available.