TLV SJ3FNB and SJ3FVB are reliable and durable ductile cast iron free float steam traps with tight shut-off for use on small to medium process equipment. The SJ3FNB is designed for horizontal piping installation, while the SJ3FVB is designed for vertical piping installation. They feature an integral plate-type bimetal air vent unit for rapid startup.

The self-modulating free float provides continuous, smooth, low velocity condensate discharge as process loads vary. A precision-ground float, constant water seal, and three-point seating design ensure a steam-tight seal, even under no-load conditions. The built-in screen with a large surface area ensures extended trouble-free operation, and easy, inline access to internal parts simplifies cleaning and reduces maintenance costs.

Specifications and Materials

No.	Description	Material	DIN	ASTM/AISI
1	Body	Ductile Cast Iron GGG40.3	0.7043	A395 Gr.60-40-18
2	Cover	Ductile Cast Iron GGG40.3	0.7043	A395 Gr.60-40-18
3	Float	Stainless Steel SUS316L	1.4404	AISI316L
5	Orifice Gasket	Fluorine Resin PTFE	PTFE	PTFE
6	Screen	Stainless Steel SUS304	1.4312	AISI304
8	Cover Gasket	Fluorine Resin PTFE	PTFE	PTFE
17	Bimetal Plate	-	-	-

WARNING

To avoid abnormal operation, accidents or serious injury, DO NOT use this product outside of the specification range. Local regulations may restrict the use of this product to below the conditions quoted. Maximum allowable pressure (PMA) and maximum allowable temperature (TMA) are PRESSURE SHELL DESIGN CONDITIONS, NOT OPERATING CONDITIONS.

Dimensions

SJ3FNB Flanged (Horizontal)

DN (DIN 2501 PN25/40)	L (mm)	H (mm)	W (mm)	B (mm)	Weight (kg)
15	150	160	180	100	6.0
20	150	160	180	100	6.4
25	160	160	185	100	6.9

SJ3FVB Flanged (Vertical)

DN (DIN 2501 PN25/40)	L (mm)	W1* (mm)	B1* (mm)	Weight (kg)
15	150	155	70	5.1
20	150	155	70	5.6
25	160	155	70	6.3

(Approximate values)

Discharge Capacity

INFO

1. Line numbers within the graph are orifice numbers.
2. Differential pressure is the difference between the inlet and outlet pressure of the trap.
3. Capacities are based on continuous discharge of condensate 6°C below saturated steam temperature.
4. Recommended safety factor: at least 1.5.

Configuration

SJ3FNB (Horizontal)

SJ3FVB (Vertical)

Proper Installation and Piping

1. Before installation, be sure to remove all protective seals.
2. Install the steam trap within the allowable inclination. Make sure that the arrow mark on the body corresponds with the direction of flow.
3. Before installing the trap, blow out the inlet piping to remove all dirt and oil.
4. Install the trap in the lowest part of the pipeline or equipment so the condensate flows naturally into the trap by gravity. The inlet pipe should be as short and have as few bends as possible.
5. Support the pipes properly within 800 mm (2.5 ft) on either side of the trap.
6. Install a bypass valve to discharge condensate, and inlet and outlet valves to isolate the trap in the event of trap failure or when performing maintenance.
7. Install a check valve at the trap outlet whenever more than one trap is connected to the condensate collection pipeline.

Piping Arrangement Checklist

• Install a catchpot with the proper diameter.
• Make sure the flow of condensate is not obstructed.
• To prevent rust and scale from flowing into the trap, connect the inlet pipe 25 - 50 mm (1 - 2 in) above the base of the T-pipe.
• When installing on the blind end, make sure nothing obstructs the flow of condensate.

Inspection and Maintenance

Operational inspections should be performed at least twice per year, or as called for by trap operating conditions. Steam trap failure may result in temperature drop in the equipment, poor product quality or losses due to steam leakage.

DANGER

NEVER apply direct heat to the float. The float may explode due to increased internal pressure, causing accidents leading to serious injury or property and equipment damage.

Part	Inspection Procedure
Body, Cover	Check inside for damage, dirt, grease, oil film, rust or scale
Gaskets	Check for warping or damage
Bimetal Unit	Check for damage
Screen	Check for clogging, corrosion or damage
Float	Check for deformation, damage, oil film or water inside
Air Vent Valve Seat, Orifice	Check for rust, scale, oil film, wear or damage

Tightening Torques (SJ3FNB / SJ3FVB)

Part	Torque (N·m)	Distance Across Flats (mm)
Cover Bolt	60	16, 17
Orifice	40	17
Screen Holder	140	24 (SJ3FNB) / 38 (SJ3FVB)
Drain Plug	30	12
Element Cover	140	32
Air Vent Valve Seat	35	19
Orifice Plug (SJ3FNB)	140	38

Troubleshooting

If the expected performance is unachievable after installation, check the following points:

Problem	Cause	Remedy
No condensate is discharged or discharge is poor	Float is damaged or filled with condensate	Replace the float
	Orifice, screen or piping is clogged with rust or scale	Clean
	Steam-locking has occurred	Blowdown through the bypass or close the trap inlet valve and allow the trap to cool
	Bimetal element is damaged	Replace the bimetal unit
	Operating pressure exceeds maximum specified pressure, or insufficient differential pressure	Compare specifications and actual operating conditions
Steam is discharged or leaks from the trap outlet	Rust and scale have accumulated around the orifice or under the float	Clean
	Orifice is damaged	Replace the orifice
	Float is deformed or coated with scale	Clean or replace the float
	Trap is installed above the maximum allowable inclination angle	Correct the installation
	Vibration of trap occurs	Lengthen inlet piping, then fasten it securely
Steam leaks from a place other than the trap outlet	Deterioration of or damage to gaskets	Replace with new gaskets
	Improper tightening torque for cover was used	Tighten to the proper torque