Each of these forces working against the other and following the saturated steam curve place into operation deflection of the bimetallic elements. In Thermidaire Steam Trap the patented Bi-Disc Gage Unit has discs placed in pairs with sides of the smaller thermal expansion facing each other. This feature gives double valve lift of each plate and may be multiplied with as many more discs as necessary. Each plate in itself is strong and has sufficient strength to hold the valve shut against steam pressure. With the discs placed in this position greater capacity is obtained as well as less chance of unequal wear to the valve and seat. This is achieved since the expanding Center of each disc aligns itself with the orifice, permitting the valve to close on the seating surface with equal force.

A. Starting up cold 0-212 Degrees P.; Only pressure is in action and the valve is open to the maximum clearance forcing both air and cold condensate rapidly through the orifice.
B. Steam enters the trap; The temperature of the condensate rises and the thermal pull of the bimetallic elements due to steam heat acting on them deflects enough to close the valve against the line pressure.
C. Condensate renters the trap; The temperature drops lessening the thermal pull of the bimetallic discs and again condensate and gases pass through the orifice.

Operation of the sensitive bimetal illustrates the closing force developed at saturated steam temperatures in relation to the line pressure working against the valve and acting to open it. The slow increase of force within the bimetal element tends to maintain the delicate balance of opening and closing the orifice. At no point can the pressure of steam overcome the closing force of the Thermidaire bimetallic thermostat. Therefore, a uniform steam-saving operation is achieved through-out the entire range without adjustment. Thermidaire multi-disc design was developed for the purpose of having each pair of thermostats operate independently of each other and utilizing that portion of the bimetal necessary to overcome the opening force of steam temperatures along the saturated steam curve. A single bimetal strip would have a straight line characteristic and would react only to large temperature differentials. Spacers placed between each pair of discs permits an equal measure of saturated or super heated temperature to impinge on all surfaces for uniform deflection. Heat transfer is maximized for instant response without the loss of steam. Thermidaire's unique variable orifice will automatically adjust to meet the exact demands at that moment. As the trap modulates continuously, the regulated flow of condensate at reduced temperatures will discharge with low velocity through a restricted opening effectively controlling temperatures in the equipment being heated.

Thermidaire Steam Traps are factory set and tested to discharge condensate between 180 degrees F. and 210 degrees F. with no steam loss. As the steam trap is designed to vent condensate and air continuously under saturated steam conditions, condensate at these low temperatures will flash giving the impression that steam is escaping. This in not the case. However, the dryer or less saturated the entering steam may be, the lower amount of flashing will be evident or none visible at all. With super heated steam the higher temperatures reacting on the thermostat produce greater thermal pull of the valve closing it tighter against the seat. A test device such as an infrared thermometer placed in the flow path will confirm low efficient operating temperatures for which Thermidaire is noted.
The standard factory setting of the cage unit assembly is made by inserting a gauge between the top disc and lock nut and tightening down until a spacing distance of 3/16" is achieved. The thermostat should be allowed to cool before attempting adjustment and preferably at room temperature, as the extreme sensitivity of the Thermidaire bimetal may give an inaccurate setting under elevated temperatures. Lower or higher discharge temperatures maybe required and in this case tightening the lock nut half turns will reduce condensate temperatures or loosening will increase temperatures.

Most plants have a variety of applications where standardization is a must in order to reduce an expensive investment in repair parts. Thermidaire fulfils this requirement with steam traps covering a single pressure and temperature range that can be used on either a radiator or a high pressure process line without having to adjust the trap to the existing conditions. Modifications also may be made in accordance to customer's specific requirements. With the ability of discharging large quantities of condensate, air is easily vented from the system since it is cooler than the steam and reacts in a similar manner as condensate to cool the bimetal element. This advantage is another reason for Thermidaire's universal appeal for use on drip legs, steam tracing, jacketed kettles, platen presses, unit heaters, tank coils, heat exchangers, drum dryers and many more applications.

The NDS can be installed on either high or low capacity steam lines from vacuum to 300 PSI. The double disc design originated by Thermidaire works quietly, effectively with a corrosion resistant bimetal thermostat. Condensate discharge modulates through a 1/2" or 5/8" orifice with no loss of steam. For reduced capacities our one piece cage unit assembly with a 1/4" orifice can be substituted. All valves are heat treated and hardened for greater wear resistance and will lap to the seating surface for a tight seal.

SPECIAL FEATURES

One piece cage unit assembly - contains thermostat, air vent and check valve easily replaced in the field.

Floating valve - rotates to clean seating surfaces and prevents clogging of the orifice

Freeze proof - self draining installed vertically otherwise can be placed in any position.

Strainer - Large capacity "Y" type with 1/2' blow down plug

Internal parts - Stainless steel with bimetal discs resistant to distortion and fatigue

Eliminates water hammer - With fast respond to changing load demands.

Anti seize lock nut - Adjust to meet unusual operating conditions

DIMENSIONS

Size NPT       A            B           C           Wt. lbs.
    1/2"        5-1/2"    5-7/8"    3-1/4"            6
    3/4"        5-1/2"    5-7/8"    3-1/4"            6
    1"          6-3/8"    5-7/8"    3-1/4"          6-1/2
Socket weld connections available

OPERATING CONDITIONS

Pressure Range 0 to 300 PSI @650 F.
Maximum Body Pressure 600 PSI.

SPECIFICATIONS

Body and Cover - Ductile Iron Valve & Seat.
Stainless Steel Bimetal
Stainless Steel Lock Nut
Silver Plated Stainless Steel Strainer
Stainless Steel Strainer Cap, Steel Gaskets
Cover - Spiral Wound and Non Asbestos/Stainless Steel, Strainer and Seat - Jacketed Non Asbestos/Stainless Steel

The ND steam trap is identical to the type NDS with the exception of the built in ~Y,, strainer. Parts are interchangeable between these traps resulting in reduced inventories and overhead expenses. Thermidaire provides a perfect approach with a design capable of replacing other make steam traps operating under similar conditions. Placing the trap in any position eliminates extra piping connections with the added advantage of a steam trap combining an air vent and a check valve in a single light weight unit.

BENEFITS

Compact - Easy to install in close areas
Vents air and non condensable - to maintain even temperatures and prevent water hammer.
Cage unit - one piece stainless steel calibrated assembly replaced on the line.
Orifice selection -  provides maximum discharge with no steam loss
Double discs - opposing each other give twice the valve clearance to eliminate blockage with greater capacity.
Mounts in any position - vertically for self draining freeze protection.
Angular position - of cage unit gives even flow less turbulence.
Valve heat treated - stiletto seat available for tough wear resistance.

DIMENSIONS

Size NPT      A            B          C          Wt. lbs.
    1/2"            4        3-3/4"    3-1/4"            4
    3/4"            4        3-3/4"    3-1/4"            4
    1"           4-1/2"        4"      3-1/4"        4-1/2

Socket weld connections available

OPERATING CONDITIONS

Pressure Range 0 to 300 PSI @650 F.
Maximum Body Pressure 600 PSI.

SPECIFICATIONS

Body and Cover - Ductile Iron Valve & Seat.
Stainless Steel Bimetal
Stainless Steel Lock Nut.
Silver Plated Stainless Steel Gaskets Cover - Spiral . Wound and Non Asbestos/Stainless Steel
Seat - Jacketed-Non Asbestos/Stainless Steel

· Simple to repair with few parts to replace and no gaskets
· An all position trap - vertical makes it freeze proof
· Compact - trap, strainer, check valve, air vent
· Fails open and safe safely relieves excessive pressure
· Resists dirt and self dealing with no water hammer or steam loss

Not A Throw-Away Can be normally repaired for less than half the cost of a new steam trap.

A miniature, light weight steam trap in stainless steel features the advantages of easy inspection and quick repair. A specially designed corrosion resistant thermostatic bimetal element offers immediate response to even the slightest temperature change.

Traps are factory set to discharge condensate at 180 to 210 degrees F. along the saturated steam curve from vacuum to 300 and 650 PSI.

When special applications require a different setting, a screwdriver can be inserted into the slotted valve head and with slight tightening of the lock nut, condensate temperatures can be sub-cooled even lower than 180 degrees P.

An adjustment in the opposite direction will increase the discharge up to 212 degrees F. with only the loss of flash steam.

The thermostat and valve are loosely assembled in the body of the trap. This flexibility permits the reverse seating check valve to rotate freely to prevent clogging of the orifice.

The types Land LS are universal steam traps useful not only for freeze protection on tracing and drip applications but also on a variety of installations.

SPECIFICATIONS

Type L & LS with Strainer Body & Trim Stainless Steel
Connections 1/4", 3/8", 1/2" 3/4", 1"

OPERATING RANGE

0 to 300 PSI @ 650⁰F.                              0 to 650 PSI @7500 F.
Orifice Size 1/4" & 1/2"                                            1/4"
Weight 12 ozs.                                                        18 ozs.
Dimensions Width 1 - 1/2"                                      1-3/4"

The DS is a rugged dependable trap machined from carbon steel bar stock with a choice of two interchangeable cage units, the same as used in the types ND and NDS steam traps. The cage unit is threaded into the end plug and is encircled with a strainer screen which easily snaps off for cleaning or repair. The hardened stainless steel valve is lapped to the seat which is made available with an optional stiletto surface for high pressures and tight seating

OPERATING CONDITIONS

Body - Carbon Steel
Internal Trim - Stainless Steel
Range - 700 PSI @750 F.
Orifice Size 1/4" & 1/2" to 300 PSI. Connections 3/8", 1/2" & 3/4"
Dimensions 4" Face to Face 2" Wide
Weight 2 lbs.

HIGH PRESSURE
BI-DISC STEAM TRAP TYPE HP & PHS

BENEFITS

In Line Maintenance - Removal of the cover exposes the one piece bi-disc assembly and strainer that surrounds the thermostat. Cleaning or replacement is accomplished in minutes.
Check Valve -  A free rotating valve seating on the down stream side closes tight on steam temperatures and excessive back pressure.

Stops Water Hammer - Sudden thermal shock and vibration due to contact of high velocity steam with cooler pockets of water is prevented with the thermostat opening the valve quickly to vent the excess water.

Long life - Internal stainless steel parts are designed to resist corrosion and where with specially bonded and nickel plated bimetal free of fatigue.

Fails safe - steam trap cannot jam shut, but will open automatically with line pressure exerted down stream against the check valve.

DETAILS OF THE TYPE HP AND PHS

Operating range 0 to 800 PSI @750 F.
Body and Cover - No.4130 Aircraft Alloy steel bar

Internal trim - Stainless steel 1/4" I.D. seat stilted with heat treated valve.
Bimetal thermostat - A special molecular bonded nickel alloy for high temperatures.

Lock nut - stainless steel silver plated
Strainer - stainless steel .045 perforations

Gaskets - Spiral wound and jacketed stainless steel with non asbestos
Cap screws - Forged steel
Connections 1/2", 3/4", 1"
Dimensions 4" 4-1/2" 3" 8
Weight 8 lbs.

INSTALL IN ANY POSITION

Vertical Installation with Check Valve pointing down makes it Freeze Proof. Tight spots also allow trap to be placed on an angle.

The Preferred Horizontal hook-up with the trap on its side allows each half of the thermostat to be exposed to steam and condensate for fast response.

All traps should be installed with at least a 3 ft. uninsulated cooling leg on the inlet side to assure a 10 to 15 degree F. temperature differential between the equipment being trapped and the steam trap itself.
Condensate can be lifted vertically to overhead return lines. One pound of steam will support 24 inches of moving water without water hammering.

Operating Capacities Pressure Range

PSI  5  10  25  50  75  100  150  200  300

Valve Orifice

Continuous Discharge lbs./hr Hot Water

1/4"      600      900      1350      2635      2850       3100      4515    5310        6800
5/16"   1175    1750      2325      4330      4600       5550      6850    8020      10800
1/2"     2750    3790      4800      8570    11750     13500     15730  18050      24100
5/8"     4775    6945      9275    17500    23675     24500     27350  32025      42800
314"    6200    8500    13000    23200    28500     34100    38080

Continuous Discharge lbs./hr Condensate @180 -210 Degrees F.

114"      230      350      525      675      735      815      1100      1315      1700
5/16"     425      635      985    1175    1300    1450      1725       2200      2850
1/2"     1250    1875    2530    3400    3835    4125      4750       5500      6100
5/8"     2075    2800    3880    5700    6260    6650      7000     10032    13500
3/4"     2575    3500    5225    6835    7520    8450      9460

Consult your representative on a steam trap survey to improve efficiency and eliminate steam leaks.

HOW TO ORDER

Specify the following:

Pipe Connection, Type, Model & Orifice Size

Example - 314", Type NDS, Model 101 with 518" Orifice (314-NDS-101-5/8)

GUARANTEE

All Thermidaire steam traps are guaranteed unconditionally for three years against defective material and workmanship.