EMERSON NFT 650 Series Steam Trap Instruction Manual
- June 4, 2024
- Emerson
Table of Contents
EMERSON NFT 650 Series Steam Trap Instruction Manual
Failure to follow these instructions or to properly install and maintain this equipment could result in property damage and personal injury or death.
The NFT 650 Series Steam Trap must be installed, operated and maintained in accordance with federal, state and local codes, rules and regulations and Emerson instructions.
If leak develops in the system, service to the unit may be required. Failure to correct trouble could result in a hazardous condition.
Installation, operation and maintenance procedures performed by unqualified personnel may result in improper adjustment and unsafe operation. Either condition may result in equipment damage or personal injury. Only a qualified person shall install or service the NFT 650 Series Steam Trap.
Introduction
Scope of the Manual
This manual provides instructions for installation, maintenance and parts information for the NFT 650 Series.
Product Description
NFT 650 Series are float and thermostatic steam traps. Float is free of levers, linkages or other mechanical connections. This float is weighted to maintain orientation and acts as the valve being free to modulate condensate through the seat ring. Air vent is balanced-pressure design with stainless steel welded encapsulated bellows capable of discharging air and non- condensable gases continuously
Figure 1. NFT 650 Series Stream Trap
within 15°F / -9.4°C of saturated temperature. Trap contains integral strainer and stainless steel exhaust port sleeve.
Principle of Operation
On startup, the thermostatic air vent (caged stainless welded bellows) is
open, allowing air to flow freely through the vent valve orifice. When
condensate flows into the trap, the float rises, allowing condensate to be
discharged. Once air and non-condensables have been evacuated, hot condensate
will cause the thermostatic vent to close. Condensate will continue to be
discharged as long as condensation occurs. During normal operation, an
increase in the load causes the liquid level in the trap to rise. The float
then rises and rolls off the seat ring, allowing more condensate to flow out.
The float sinks as the condensate load decreases, moving nearer to the seat
ring, decreasing
the effective size of the orifice and allowing less condensate to discharge.
This provides smooth, continuous operation that reacts instantly to load
variation while maintaining a water seal over the seat ring to prevent live
steam loss.
Specifications
The specifications section on this page provide the ratings and other specifications for the NFT 650 Series.
Table 1. Maximum Operating Pressure
Installation
Install the NFT 650 Series Steam Trap upright and in a horizontal line with the arrow on the body pointing in the direction of flow. Allowable inclination is 5° or less horizontally and 5° or less at right angles to the plane of the pipe line.
Maintenance
Due to normal wear that may occur, inspect the parts periodically and replace if necessary. The frequency of inspection depends on the severity of service conditions.
Inspection of the thermostatic bellows is not recommended as disassembly generally damages the unit.
- Disassemble the steam trap. Remove the body bolts and place the lower body on a safe place.
- Inspect the float and lower seat ring for damage and clean or replace as necessary. Clean the float with a rag and steel wool.
- Clean the screen using a wire brush.
- Replace bellows if needed. Use needle nose pliers or similar tool. Insert them into two of the three holes located in the bellows assembly and unscrew it from the upper body.
Note When reassembling, use thread locker on the bellows assembly threads.
- After inspection/repair, reassemble trap, replacing body gasket and torquing bolts as specified. See Table 2.
Figure 2. NFT 650 Series Stream Trap Operational Schematic
Table 2. NFT 650 Series Stream Trap Torque Values
Parts Ordering
When corresponding with your local Sales Office about NFT 650 Series Steam Trap, always reference the assembly number. When ordering replacement parts, specify the complete character part number from the following parts list.
Parts List
Figure 3. NFT 650 Series Steam Trap Assembly
Key 1, NFT 650 Series Body Part Number
Key 7, NFT 650 Series Seat Ring Part Number
VCIMD-14910 © 2021, 2022 Emerson Electric Co. All rights reserved. 04/22 Spence is a mark owned by one of the companies in the Emerson Automation Solutions business unit of Emerson Electric Co. The Emerson logo is a trademark and service mark of Emerson Electric Co. All other marks are property of their prospective owners.
The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. All sales are governed by our terms and conditions, which are available upon request. We reserve the right to modify or improve the designs or specifications of such products at any time without notice.
Emerson Electric Co. does not assume responsibility for the selection, use or maintenance of any product. Responsibility for proper selection, use and maintenance of any Emerson Electric Co. product remains solely with the purchaser.
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