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Ductile Cast IronFree FloatThermostatic Air VentingInline Repairable

TLV SJ7FNX / SJ7FVX Free Float Steam Trap

TLV SJ7FNX and SJ7FVX ductile cast iron free float steam traps with three-point seating and thermostatic air venting for medium-size process equipment.

TLV SJ7FNX / SJ7FVX Free Float Steam Trap

The TLV SJ7FNX and SJ7FVX are ductile cast iron free float steam traps with three-point seating and thermostatic air venting (X-element). They are reliable and durable steam traps with tight shut-off, designed for use on medium-size process equipment such as heat exchangers, tank heaters, dryers, and process equipment. The SJ7FNX is designed for horizontal piping installation, while the SJ7FVX is designed for vertical piping installation.

These inline repairable traps discharge condensate continuously and automatically at a temperature slightly lower than saturation temperature. 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 thermostatic capsule (X-element) with a "fail open" feature vents air automatically until close-to-steam temperature. A 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.

TLV SJ7FNX / SJ7FVX cross section

Specifications

ModelSJ7FNXSJ7FVX
InstallationHorizontalVertical
ConnectionFlangedFlanged
SizeDN 40, 50DN 40, 50
Orifice No.2, 5, 9, 14, 222, 5, 9, 14, 22
Maximum Operating Pressure (PMO)2, 5, 9, 14, 22 barg2, 5, 9, 14, 22 barg
Maximum Differential Pressure (ΔPMX)2, 5, 9, 14, 22 bar2, 5, 9, 14, 22 bar
Maximum Operating Temperature (TMO)220 °C220 °C
Subcooling of X-element Fillup to 6 °Cup to 6 °C
Type of X-elementC6C6

WARNING

PRESSURE SHELL DESIGN CONDITIONS (NOT OPERATING CONDITIONS):

  • Maximum Allowable Pressure (PMA): 22 barg
  • Maximum Allowable Temperature (TMA): 220 °C
  • Minimum Allowable Temperature: 0 °C

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.

Materials

No.DescriptionMaterialDINASTM/AISI
1BodyDuctile Cast Iron GGG40.3/EN 5.31030.7043A395 Gr.60-40-18
2CoverDuctile Cast Iron GGG40.3/EN 5.31030.7043A395 Gr.60-40-18
3Cover GasketFluorine Resin PTFEPTFEPTFE
4FloatStainless Steel SUS316L1.4404AISI 316L
5Orifice---
6Orifice GasketFluorine Resin PTFEPTFEPTFE
7X-element ScreenStainless Steel SUS3041.4301AISI 304
8ScreenStainless Steel SUS4301.4016AISI 430
9Screen HolderCast Stainless Steel A351 Gr.CF81.4312-
10Screen Holder GasketSoft Iron SUYP1.1121AISI 1010
11Orifice Plug (SJ7FNX)Cast Stainless Steel A351 Gr.CF81.4312-
12Orifice Plug Gasket (SJ7FNX)Soft Iron SUYP1.1121AISI 1010
13Drain PlugCarbon Steel SS4001.0037A6
14X-elementStainless Steel--
15X-element GuideStainless Steel SUS3041.4301AISI 304
16X-element CoverCast Stainless Steel A351 Gr.CF81.4312-
17Air Vent Valve SeatStainless Steel SUS420F1.4028AISI 420F
18Cover BoltCarbon Steel S45C1.0503AISI 1045
19Spring ClipStainless Steel SUS3041.4301AISI 304
20X-element Cover GasketFluorine Resin PTFEPTFEPTFE
21NameplateStainless Steel SUS3041.4301AISI 304

Dimensions

SJ7FNX Flanged (Horizontal)

TLV SJ7FNX / SJ7FVX TLV SJ7FNX dimensions

DNL (DIN 2501 PN25/40)H1WBWeight (kg)
40230 mm312 mm346 mm205 mm26
50230 mm312 mm346 mm205 mm28

SJ7FVX Flanged (Vertical)

TLV SJ7FNX / SJ7FVX TLV SJ7FVX dimensions

DNL (DIN 2501 PN25/40)W1BWeight (kg)
40230 mm304 mm205 mm22
50230 mm304 mm205 mm23

Discharge Capacity

TLV SJ7FNX / SJ7FVX discharge capacity

INFO

  1. Line numbers within the graph refer to 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.

WARNING

DO NOT use this product under conditions that exceed maximum differential pressure, as condensate backup will occur!

Proper Installation

  • Installation, inspection, maintenance, repairs, disassembly, adjustment and valve opening/closing should be carried out only by trained maintenance personnel.
  • Take measures to prevent people from coming into direct contact with product outlets.
  • Install for use under conditions in which no freeze-up will occur.
  • Install for use under conditions in which no water hammer will occur.
  1. Before installation, be sure to remove all protective seals.
  2. Install the steam trap within the allowable inclination. Also 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.

TLV SJ7FNX / SJ7FVX TLV SJ7FNX horizontal installation

TLV SJ7FNX / SJ7FVX TLV SJ7FVX vertical installation

Piping Arrangement

RequirementCorrectIncorrect
Install a catchpot with the proper diameter.Diameter is adequate.Diameter is too small.
Make sure the flow of condensate is not obstructed.Flow is clear.Diameter is too small and inlet protrudes into pipe.
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.Connected above base.Rust and scale flow into the trap with the condensate.
When installing on the blind end, make sure nothing obstructs the flow of condensate.Flow is clear.Condensate collects in the pipe.

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.

Parts Inspection Procedure

PartInspection Item
Body, CoverCheck inside for damage, dirt, grease, oil film, rust or scale
GasketsCheck for warping or damage
X-elementCheck for damage
ScreenCheck for clogging, corrosion or damage
FloatCheck for deformation, damage, oil film or water inside
Air Vent Valve Seat, OrificeCheck for rust, scale, oil film, wear or damage

Tightening Torques and Distance Across Flats

PartTorque (N·m)Distance Across Flats (mm)
Cover Bolt10024
Orifice12030
Screen Holder40050
Drain Plug3012
X-element Cover14032
Air Vent Valve Seat3519
Orifice Plug40050

Operational Check

A visual inspection can be carried out to aid in determining the necessity for immediate maintenance or repair, if the trap is open to atmosphere.

  • Normal: Condensate is discharged continuously with flash steam and the sound of flow can be heard. If there is very little condensate, there is almost no sound of flow.
  • Blocked: No condensate is discharged. The trap is quiet and makes no noise, and the surface temperature of the trap is low.
  • Blowing: Live steam continually flows from the outlet and there is a continuous metallic sound.
  • Steam Leakage: Live steam is discharged through the trap outlet together with the condensate and there is a high-pitched sound.

Troubleshooting

ProblemCauseRemedy
No condensate is discharged or discharge is poorFloat is damaged or filled with condensateReplace the float
Orifice, screen or piping is clogged with rust or scaleClean
Steam-locking has occurredBlowdown through the bypass or close the trap inlet valve and allow the trap to cool
X-element is damagedReplace the X-element
The trap operating pressure exceeds the maximum specified pressure, or there is insufficient pressure differentialCompare specifications and actual operating conditions
Steam is discharged or leaks from the trap outletRust and scale have accumulated around the orifice or under the floatClean
Orifice is damagedReplace the orifice
Float is deformed or coated with scaleClean or replace the float
Trap is installed above the maximum allowable inclination angleCorrect the installation
Vibration of trap occursLengthen inlet piping, then fasten it securely
The X-element is damaged, or clogged with rust or scaleClean or replace the X-element
Steam leaks from a place other than the trap outletDeterioration of or damage to gasketsReplace with new gaskets
Leakage from eroded cavities of body or coverReplace the trap
Improper tightening torque for cover was usedTighten to the proper torque
Float is frequently damagedWater hammer occursExamine the piping for problems that can cause water hammer

Option (Integral Plate-type Bimetal Air Vent Unit)

Models SJ7FNB and SJ7FVB feature an integral plate-type bimetal air vent unit.

TLV SJ7FNX / SJ7FVX TLV SJ7FNB / SJ7FVB bimetal option configuration

Disassembly/Reassembly of the Bimetal Section

PartDisassemblyReassembly
Element CoverRemove with a socket wrenchConsult the table of tightening torques and tighten to the proper torque
Element Cover GasketRemove the gasket and clean sealing surfacesReplace with a new gasket
Spring ClipPinch the insides together and remove from the element guideInsert it securely into the groove
Bimetal Unit-Insert the bimetal unit into the element guide with "T" mark on the bimetal facing towards the air vent valve seat.
Air Vent Valve Seat (for Bimetal)Remove with a socket wrenchConsult the table of tightening torques and tighten to the proper torque

Table of Tightening Torques (Bimetal Unit)

PartTorque (N·m)Distance Across Flats (mm)
Element Cover14032
Air Vent Valve Seat3519