Understanding Valves, Strainers, and Steam Traps

Bypass valve

Allows flow around clogged filter element.

Micron

1/1,000,000 meter measurement.

Geometric strainers

Require disassembly for inspection and cleaning.

Excess pressure differential

Indicates strainer needs cleaning.

Magnets in strainers

Attracts metal particles from reduction gears.

Spiral wound flexitalic

Used for high pressure steam flange joints.

Packing puller

Tool for removing valve stuffing box packing.

Lube oil strainers

Remove ferrous metallic particles from oil.

Dirty fuel oil strainer

Indicated by decreasing pressure drop.

Packing gland length

Secured with 2 1/2 inches length.

Sealing water supply

Provided to the lantern ring.

Duplex pressure gauge

Shift to clean strainer basket if pressure differs.

Scored valve stem

Causes excessive leakage and valve packing failure.

Packing installation

Cut square and staggered 90 degrees apart.

Cleaning duplex strainer

Bleed off pressure before opening cover.

Strainer cleaning guideline

Clean when pressure drop reaches 10 psi.

Bimetallic steam trap

Uses two dissimilar metals for operation.

Temperature indicating crayon

Tests steam trap by melting at outlet.

Thermostatic disc trap

Cannot provide tight shut off, leaks steam.

Thermodynamic impulse trap

Water flow depends on condensate temperature.

Vapor pressure effect

Reduces condensate flow through steam trap.

Steam trap purpose

Drains low points to keep steam line dry.

Water hammer cause

Steam entering a cold pipe.

Steam trap insulation

Must not be insulated for proper operation.

Bellows type thermostatic steam trap

Operates on expansion and contraction of sealed chamber.

Steam trap installation

Install at lowest outlet for maintenance access.

Bucket type steam trap

Operates based on specific design principles.

Sinking Bucket

Opens the valve by descending in water.

Thermostatic Steam Trap

Operates on thermal expansion of a fluid.

Impulse Steam Trap

Uses rapid vapor pressure reduction to function.

Water Hammer

Result of a steam trap failing closed.

Steam Trap Function

Limits steam flow until latent heat is released.

Bellows

Not a major class of steam traps.

Steam Loss

Occurs if a steam trap fails open.

Trap Test Valve

Water out indicates steam trap is functional.

Drive Gear Ratio

25 teeth drive 100 teeth gear at 4x rate.

Reducing Valve

Automatically lowers supply pressure to a set level.

Relief Valve

Opens gradually with increased pressure changes.

Diaphragm Valve

Uses a diaphragm to control flow.

Safety Valve

Most critical valve on a boiler system.

Pilot-Operated Valve

Offers accurate pressure sensing and responsiveness.

Safety vs. Relief Valve

Safety valves reseat only after significant pressure drop.

Pneumatic Control Valve

Operates between 0-30 psi air pressure signals.

Globe Valve Flow Direction

Flow should be from below the valve seat.

Butterfly Valve Handle Position

Must be parallel to flow when fully open.

Reach Rod Purpose

Operates valves that are out of reach.

Blowdown Definition

Difference between popping and reseating pressure.

Needle Valve

Best for precise flow metering.

Plug Valve

Used for non-throttling on/off operations.

Diaphragm Advantage

Isolates moving parts from process fluid.

Check Valve Classes

Wafer is not a main class of check valves.

Globe Valve Disc Design

Plug design is best for regulating flow.

Welded

Refers to how the stem moves in a valve.

Flanged Joint Preparation

Use new gasket, align flanges, tighten bolts.

Valve Trim

Components guiding the stem: disc, seat, bushing.

Valve Bonnets

Attached by methods excluding welded connections.

Gate Valve

Non-rising stem with internal screw mechanism.

Expansion Joints

Packled joints require more maintenance than sliding.

Flange Types

Flat faced for low-medium, raised face for medium-high pressure.

Copper Tubing Thickness

Thicker wall is closer to letter Z.

Gate Valve Attributes

Cannot regulate or throttle flow effectively.

Union Fitting

Allows easy disconnection of piping sections.

Butterfly Valve

Wafer type designed for quick shut-off.

Heat Transfer Types

Sublimation is not a type regarding valves.

Weir Type Diaphragm Valve

Uses a weir to control flow.

Lift Check Valve

Allows flow in one direction, prevents backflow.

Motor Operated Valve

Automated valve controlled by electric motor.

Duplex Strainers

Have a plug valve for switching strainers.

Solenoid Valve

Best suited for full open or closed states.

Valve Actuators

Exclude kinetic types in actuator categories.

Latent Heat

Heat causing state change without temperature change.

Spectacle Flange

Allows complete flow or complete shut-off.

Expansion Joints Purpose

Accommodate expansion and contraction in pipelines.

Split Wedge Valve

Self-aligning gate for better sealing performance.

Valve Performance

Determined by condition of disc and seat.

Flanged Joint Alignment

Ensure flanges are squarely aligned before assembly.

Pipe Fittings Welding Angle

Bevel machined at 37.5 degrees for welding.

Welding Methods

Includes wire feed and stick welding techniques.

Weld Neck Flange

Best for high pressure and temperature applications.

Steel Pipe Schedule

Schedule 120 has the thickest wall.

Duplex Strainer Usage

Used in critical systems needing continuous operation.

Lubricated Plug Valve Consideration

Lubricant must match fluid compatibility.

Glove Valve Classification

Excludes unspecified body types.

Butterfly Valve Design

Permits disconnection without disturbing flanged connections.

Lug style butterfly valve

A valve type for regulating flow in pipes.

Assembly drawing

Illustration showing components in a detailed layout.

High pressure systems

Pipe systems designed to handle elevated pressures.

1/4-20 NC-2

Thread specification indicating diameter and pitch.

Extra fine threads

Most threads per inch for tighter fit.

Thread pitch gage

Tool to measure threads per inch accurately.

Box end wrench

Wrench type preventing slipping while tightening.

Torque wrench

Tool for tightening bolts to specified tension.

Deflecting beam torque wrench

Reads torque on a scale mounted on handle.

Clockwise rotation

Direction to close handwheel-operated valves.

Nominal inside diameter

Standard sizing for piping cross sections.

Solder

Low melting point alloy used in soldering.

840°F melting point

Threshold separating soldering from brazing processes.

Capillary action

Mechanism drawing solder into fittings during soldering.

Lap joint flange

Flange allowing independent bolt hole circle movement.

Compression fitting

Fitting type requiring ferrules for assembly.