4-20 mA Current Loops: The Complete Instrument Tech Guide
How 4-20 mA current loops work, why 4 mA is live zero, how to convert between signal and process values, and how to detect loop faults.
Guides & How-To
Practical context for the calculators: where the math comes from, what assumptions matter, and which tool to run next.
Showing Shops & Outbuildings guides. 87 shown.
Shops & Outbuildings
87 guidesASTM Pipe Specs Explained
What A106, A53, A312, A333, A335, and A790 actually mean: seamless vs welded, high-temperature vs low-temperature service, and why A106 and A53 are not interchangeable.
Bearing Decoder Guide: Read SKF, FAG, Timken, NSK, NTN, Koyo Numbering
How to read a bearing part number across all six major makers. Bore code rule, suffix categories, intent-level cross-vendor translation, clearance class microns from ISO 5753-1, legacy brand aliases (Fafnir, MRC, Bower, RHP). Companion to the Bearing Part Number Decoder.
Bearing Failure Modes: Reading the Evidence
How to tell what killed a bearing by looking at the damage pattern. Fatigue spalling, lubrication failure, contamination, electrical fluting, and corrective actions.
Bearing Fits: Why Thousandths of an Inch Matter
How to review shaft-fit source boundaries, why loose or tight fits create different risks, and what manufacturer, drawing, inspection, and thermal gaps control.
Bearing Grease: Choosing the Right One and Knowing When to Apply It
Base oil viscosity, NLGI grade, thickener type, regreasing intervals, and why over-greasing causes as many failures as under-greasing.
Bearing Installation: Getting It Right Without Damaging the Bearing
Pressing, heating, pulling, and the installation mistakes that create the next failure. When to use an induction heater versus a hydraulic press.
Bearing Life Calculations: What L10 Actually Means
Why calculated bearing life and actual bearing life are often very different numbers, what L10 predicts, what it misses, and how to use it for maintenance planning.
Bearing Loads: How to Calculate What Your Bearing Actually Sees
Radial loads, axial loads, X and Y factors, belt tension, gear mesh forces, and the loads people commonly forget in bearing life calculations.
Bearing Lubrication Intervals: SKF Source Boundaries & Grease Selection
How SKF relubrication guidance uses speed factor, bearing factor, load ratio, temperature, contamination, grease quantity factors, and OEM review.
Bearing Removal Force: How Much Pull Does It Take?
Estimating press and pull force for safe bearing installation and removal. When to use mechanical pullers, hydraulic pullers, or induction heating.
Bearing Speed Limits: What ndm Means and Why It Matters
How to check if your bearing is running too fast for the lubrication method, what ndm represents, and what to do when grease cannot keep up with the speed.
Belt Drive Sizing: Speed Ratios, Belt Length & Sheave Selection
How V-belt drives work, calculating speed ratios, selecting belt cross-sections, determining belt length, and troubleshooting common belt drive problems.
Bolt Torque vs Tension: K-Factor, Preload & Lubrication Effects
Understanding the relationship between applied torque and bolt tension. K-factor (nut factor), lubrication effects, preload targets, and why 90% of your torque is friction.
Bolt Torque: Why Lubrication Changes Everything
K-factor explained for working mechanics, the dramatic effect of dry vs oiled vs anti-seize, Grade 5 vs 8, fine vs coarse thread tradeoffs, and torque wrench basics.
CMU Block Estimating: Block Count, Mortar, Grout, and Rebar
How to estimate CMU block quantities for masonry walls. Block count per square foot, mortar bags, grout fill, rebar requirements, and waste factors.
Center of Gravity: Calculating CoG for Unbalanced and Composite Loads
How to calculate center of gravity for asymmetric loads, determine sling length ratios for level lifts, and predict tilt angles. Composite body method explained.
Control Valve Cv Sizing: Liquid, Gas & Steam
How to calculate valve Cv for different fluid types, detect choked flow conditions, and match Cv to standard valve sizes.
Coupling Alignment: Offset, Angularity & Tolerance by Type
Shaft alignment fundamentals: offset vs angularity, tolerance standards by coupling type, rim-and-face vs reverse indicator vs laser methods, and thermal growth compensation.
Deck Building Materials: Board Count, Fasteners, and Joist Layout
How to calculate deck board quantities, fastener counts, and joist requirements. Perpendicular, parallel, and diagonal layouts with waste factors.
Fillet Weld Strength Planning
Effective throat vs leg size, AWS D1.1 allowable stresses, the cost of overwelding, base metal shear failure, and why increasing weld length beats increasing weld size.
Fisher Control Valve Decoder Guide: Bodies, Actuators, FIELDVUE, and 627 Regulators
How to read a Fisher control valve assembly tag across body, actuator, positioner, and regulator. Covers the easy-e family map, fail-action derivation, shutoff-class references, NACE and ENVIRO-SEAL verification, DVC6200 construction-specific approval checks, and the 627 Series regulator portfolio.
Flange Bolting: B16.5-Style Patterns, Gaskets & Source Boundaries
Flange bolting concepts for B16.5-style joints, gasket and face selection, tightening sequence, PCC-1 review, and source-boundary warnings.
Flooring Material Source Guide: Carpet, LVP, Laminate, and Hardwood
Carpet seam planning for 12-foot rolls, plank direction waste, stagger requirements, moisture barriers, underlayment selection, and stair material takeoff.
Garage Door Opener Selection: HP Sizing, Drive Types, and Installation Requirements
Door weight by material, horsepower selection rules, chain vs belt vs screw vs jackshaft drive comparison, spring balance testing, smart features, and electrical requirements.
Gas Cylinder Duration Planning Guide
Plan compressed-gas cylinder run time from local cylinder-volume and flow assumptions before supplier and safety review.
Generator Backfeed and Transfer Equipment Source Checks
Backfeed hazard paths, transfer-equipment source checks, interlock review, CO placement, utility coordination, and AHJ boundaries before generator use.
Gutter Sizing Planning Guide
How to size gutters and downspouts for any roof. Rainfall intensity, roof area calculations, pitch factors, and IPC/UPC drainage requirements.
Gutter and Downspout Planning: Capacity, Rainfall, and Maintenance
IPC gutter capacity tables, NOAA Atlas 14 rainfall intensity by region, downspout spacing rules, gutter guard impact on capacity, and ice dam prevention.
Hardness Testing: Rockwell, Brinell, Vickers & When to Use Each
Understanding hardness test methods: Rockwell (HRC/HRB), Brinell (HB), Vickers (HV), and Shore, with conversion caveats and specified-test guidance.
Heat Exchanger Basics: LMTD, UA, Fouling & Approach Temperature
Understanding heat exchanger duty calculations: LMTD method, UA rating, fouling factors, approach temperature, and when to clean or replace exchangers.
How Speeds and Feeds Actually Work
SFM and chip-load fundamentals with local-row limits, toolmaker data, machine capability, workholding, coolant, and setup-review boundaries.
How to Measure for Wallpaper: Pattern Repeats, Waste, and Roll Counts
Pattern match types explained, repeat waste calculation, dye lot importance, peel-and-stick considerations, and room measuring techniques for accurate wallpaper ordering.
How to Read AWS Welding Electrode Numbers
What the digits and letters on a welding rod or wire mean: tensile strength, welding position, the last two digits for coating and current, low-hydrogen status, and the difference between E7018, ER70S-6, and E71T-1.
I/P Converter Output Checks: Source-Gap Guide
How to frame I/P converter output checks without treating local 4-20 mA to pressure arithmetic as calibration, repair, replacement, air-quality, or loop-safety approval.
IEC Motor Frame Guide: Frame Number Is Shaft Height, S/M/L Length, B3/B5/B14 Mounting, and the NEMA Cross-Reference
Plain-language IEC motor frame reference. The frame number is the shaft centre height in millimetres (IEC 60072-1); the S/M/L letter sets the body length and foot spacing, not the shaft height; the B3/B5/B14/B35 mounting codes; the 2-pole shaft-diameter reduction on frames 225 and larger; and why the IEC-to-NEMA cross-reference is nearest, not a drop-in. Companion to the IEC Motor Frame Decoder.
IP Rating Guide (IEC 60529): First Digit, Second Digit, K Suffix, and Supplementary Letters
Plain-language IP code reference with source limits: first digit, second digit, K suffix, supplementary letters, IP69K shorthand, why IPX9K is not NEMA 6P, and what tests IP does not include compared to NEMA.
Instrument Air Leak Audit: Find, Cost & Prioritize Repairs
How to conduct an instrument air leak survey, estimate equivalent-orifice cost, and separate DOE/CAC source-backed math from reliability, repair, and safety source gaps.
Instrument Air Line Planning: Pressure Drop & Material Checks
How to size instrument air tubing using Harris formula, compare copper vs black iron vs stainless, and avoid velocity problems in pneumatic systems.
Lathe Turning: Planning the Cut Before Review
Lathe RPM, feed, theoretical finish, G96 vs G97, depth-of-cut planning, and the machine, tooling, workholding, inspection, and safety checks still needed.
Livestock Barn Ventilation Source Boundaries
How to treat local CFM-per-head rows, fan curves, static pressure, inlets, natural ventilation, tunnel velocity, and animal-health warnings as source-bound planning context.
Lubricant Viscosity Grade Boundaries
How ISO VG, AGMA, SAE engine, SAE gear, and NLGI labels relate, with product data sheet, OEM, compatibility, and source-gap warnings.
MRO Spare Parts Inventory: Reorder Points, Safety Stock, and Storeroom Strategy
How to calculate reorder points and safety stock for maintenance spare parts, handle slow-moving items with Poisson distribution, and build a storeroom strategy that balances cost against stockout risk.
Machine Shop Electrical Planning Guide
Three-phase vs single-phase power, phase converter options, panel sizing for CNC machines, VFD electrical requirements, and grounding for machine tools.
Metal Removal Rate Planning Guide
MRR formulas for milling, turning, and drilling with source boundaries for local unit-HP rows, in-cut time, machine limits, and quote assumptions.
Motor Efficiency: Loading, Source Boundaries & Premium Comparison Review
How motor efficiency varies with load, why oversized motors waste energy, when to right-size, NEMA premium efficiency standards, and calculating annual energy savings.
Motor Nameplate Source-Boundary Guide
Field-by-field guide to reading electric motor nameplates. HP, FLA, frame size, insulation class, service factor, NEMA design, efficiency, and NEC/AHJ review boundaries.
Motor Slip Source-Boundary Guide
What motor slip is, how synchronous speed relates to actual speed, and where local NEMA design prompts stop before manufacturer data and selected-motor review.
NEMA Enclosure Rating Guide: Types 1 to 13 Plus 7/9 Hazloc and the One-Way IP Cross-Reference
Plain-language guide to ANSI/NEMA Type ratings. Covers each active Type (1, 2, 3, 3R, 3RX, 3S, 3SX, 3X, 4, 4X, 5, 6, 6P, 7, 9, 12, 12K, 13) and historical Types 8 and 10. Why NEMA-to-IP cross-reference is one-way only, the assembly-rated-at-the-weakest-fitting rule, how NEMA 4X corrosion testing differs from IP66, and the field-truth substitutions that cause rework. Companion to the NEMA Enclosure Rating Decoder.
Overhead Door Heat-Loss Source Checklist
Use overhead-door heat-loss math as a source checklist. Local seal, wind, fuel, product, and payback assumptions need measured leakage, quotes, and qualified review.
PID Tuning Basics: What Every Instrument Tech Should Know
Practical PID tuning guide for instrument technicians. Understand P, I, and D actions, interpret step responses, and apply Ziegler-Nichols and Lambda tuning methods.
Pipe Miter Template Source-Boundary Guide
How pipe miter templates work, the math behind wrap-around layouts, saddle cuts vs straight miters, and tips for accurate field cuts on round pipe.
Pipe Pressure Drop Source-Boundary Guide
How to calculate pressure drop in pipes using Darcy-Weisbach equation. Friction factor, Reynolds number, equivalent length of fittings, and practical pipe sizing.
Pipe Schedule Source-Boundary Guide
What pipe schedule numbers mean, NPS vs actual dimensions, wall thickness by schedule, material and pressure-design boundaries, and what to verify before selecting pipe.
Pipe Spool Fabrication: Takeout Source Boundaries
How to measure center-to-center and subtract fitting take-outs to calculate exact pipe cut lengths for spool fabrication.
Pneumatic Control Valve Troubleshooting: A Field Guide
How to frame pneumatic valve symptom checks while keeping manufacturer manuals, instrument-air data, safe-work controls, and qualified-review gaps visible.
Pneumatic Cylinder Sizing: Force, Speed & Air Consumption
How to calculate pneumatic cylinder force, account for friction, estimate air consumption, and select the right bore size for your application.
Pole Barn Snow Load Source Boundaries
Ground snow load vs roof snow load, exposure and thermal factors, drift loads, unbalanced loads, IBC requirements, and when you need a structural engineer.
Pump Affinity Source-Boundary Guide
Understanding local centrifugal-pump affinity prompts, system-curve limits, static-head caveats, impeller trim boundaries, VFD review, NPSH, and safety gaps.
Rafter Framing: Common, Hip, and Valley Rafter Calculations
Source-boundary guide for common, hip, and valley rafter geometry prompts, bird's mouth review limits, roof-plan gaps, and structural/safety review.
Relief Valve Sizing Source Boundaries
How to review relief-valve area prompts while separating local arithmetic from current API, ASME, manufacturer, National Board, and jurisdictional decisions.
Reviewing PM Intervals With Weibull and Source Gaps
How to use Weibull reliability analysis and cost modeling to find the PM interval that minimizes total maintenance cost. Covers data collection, parameter interpretation, and when PM is counterproductive.
Rigging Safety: Sling Angles, WLL, Safety Factors & Inspection
Rigging fundamentals for safe crane operations. Sling angle effects on tension, working load limits, safety factors by sling type, hitch configurations, and inspection criteria.
Rolling Offset Source-Boundary Guide
Centerline rolling-offset geometry, fitting-angle multipliers, takeout gaps, and safety/code boundaries for pipe layout review.
Roofing Material Source Boundaries: Squares, Slope Factor, and Waste Prompts
How to estimate roofing materials for shingles and metal panels. Slope factor, squares, bundles, underlayment, ice and water shield, and waste allowance.
Rosemount 2051 Ordering Code Guide: 2051C, 2051T, 2051G and the 2051-vs-3051 Decision
Plain-language guide to reading supported 2051C/T/G model-code rows with PDS page citations while keeping ordering, certification, hazardous-area, configuration, WirelessHART, process-compatibility, installation, and qualified-review gaps explicit.
Rosemount 3051 Decoder Guide: Read SAL and CD Model Codes Without Guessing
How to read supported Rosemount 3051SAL and 3051C model-code rows with context, seal, order, certification, configuration, and safety review gaps visible.
Rosemount 3144P Ordering Code Guide: Single vs Dual Sensor, X-well, and the HART / Fieldbus Split
Plain-language guide to reading supported Rosemount 3144P model-code rows while keeping current Emerson configurator, sensor configuration, X-well, hazardous-area, SIS, installation, and commissioning gaps visible.
Rosemount 644 Ordering Code Guide: Head, Field, Rail and the Fieldbus / Hot Backup Constraints
Plain-language guide to supported Rosemount 644 head, field, and rail model-code rows, why the sensor is not encoded, and where Fieldbus, Hot Backup, certification, configuration, installation, and qualified-review boundaries remain.
Rosemount 848T Ordering Code Guide: Channel Count, the S002 Cert Trap, and the Wireless Build
Plain-language guide to supported Rosemount 848T Rev SD rows while keeping channel-map, S002, Fieldbus host, WirelessHART network, configuration, certification, and installation review gaps visible. Companion to the Rosemount 848T Multi-Input Temperature Decoder.
Sheave & Belt Field Guide: Identifying What is Installed and What Changed
A working mechanic's guide to identifying V-belts, decoding sheave part numbers, telling QD from Taper-Lock bushings, applying affinity-law reality checks, and finding the most likely cause when a drive starts misbehaving.
Siding Material Takeoff: Accessories, Waste Factors, and Type Comparison
Vinyl vs fiber cement vs wood siding compared, J-channel and accessory takeoff, gable waste calculation, housewrap and rain screen requirements, and cost comparison by type.
Sling Tension: Angle Effects, WLL Reductions, and ASME B30.9 Requirements
How sling angle affects local tension prompts, where WLL and hitch source gaps remain, and why qualified lift-plan review is still required.
Spreader Bar & Lifting Beam: Sizing, Buckling, and Section Modulus
Preliminary sizing of spreader bars (compression) and lifting beams (bending). Euler buckling checks, section modulus requirements, and common tube properties.
Tap Drill Sizes: Why 75% Thread Is Usually Wrong
The thread percentage myth, why 60-65% thread engagement is the practical sweet spot, tap type selection, tapping stainless, and how to extract a broken tap.
Thermal Growth and Bearings: What Changes When Machines Heat Up
How temperature affects shaft fit, housing fit, alignment, and internal clearance. CTE values for common materials and when to use C3 or C4 clearance bearings.
Thinset and Grout: Trowel Selection, Coverage Rates, and Material Types
TCNA trowel size guidelines, modified vs unmodified thinset, sanded vs unsanded vs epoxy grout, back-buttering large format tile, and substrate requirements.
Valve Actuator Sizing: Torque, Thrust & Fail-Safe Verification
How to verify actuator torque or thrust against valve requirements, apply safety factors, and check spring fail-safe action for butterfly, ball, globe, and plug valves.
Valve Stroke Time: Tubing, Solenoids & System Cv
How pneumatic valve stroke time is determined by actuator volume, supply pressure, and the series Cv of solenoids and tubing. Troubleshoot slow-stroking valves.
Vibration Analysis Basics: ISO 10816, Severity Zones & Machine Classes
Introduction to machine vibration analysis. ISO 10816 severity classification, velocity vs displacement vs acceleration, machine groups, and when to act on vibration readings.
What the Markings on a Bolt Head Mean
How to read bolt head markings: SAE radial lines and the count-plus-two rule, the metric property class numbering, stainless A2/A4 corrosion classes, and ASTM structural grades.
Where Your Welding Gas Money Actually Goes
Shielding-gas planning limits, flow-rate source gaps, cylinder vs bulk quote checks, leak checks, and WPS review boundaries.
Why Weld Heat Input Matters More Than You Think
What heat input actually controls in the weld zone, cooling rate metallurgy for non-metallurgists, AWS D1.1 requirements, and how to measure travel speed accurately.
Why Your Outbuilding Motor Won't Start
How long wire runs can affect outbuilding motor starting, with voltage measurement, nameplate LRA, source impedance, starter, manufacturer, and qualified-review caveats.
Why Your Shop Compressor Runs All Day
If your compressor never shuts off, the tank is too small, the demand is too high, or you have leaks. How to figure out which one it is and whether you need a bigger compressor or just better plumbing.
Why Your Shop Is Always Cold
Review common shop heat-loss paths - doors, slabs, insulation, and air leakage - with source warnings before using the math for heater sizing or payback decisions.
Why Your Well Pump Trips the Breaker
Well pump trips can involve wire length, voltage drop, controls, capacitors, motor current, pump condition, and source/AHJ review before replacement decisions.