A tank with a circular hole of diameter d and at a depth h discharges water at a rate of Q.
The discharge rate is derived from Torricelli’s Principle and given by:
where
Q =discharge rate (m³/s)
h =depth of water (m)
A =area of opening (m²)
g =acceleration due to gravity (9.81 m/s²)
The torque required to tighten the bolt:
Where:
T: Torque (N.m)
K: Torque coefficient
F: Axial preload force (N)
d: Nominal bolt diameter (mm)
The torque coefficient:
Where:
l: Lead (mm)
α: Half angle of the screw thread (°)
d: Nominal bolt diameter (mm)
µ: Thread friction coefficient
µc: Collar friction coefficient
Common torque coefficient values for µ=µc=0.15:
| Bolt condition | K |
| Non plated black finish steel bolts | 0.3 |
| Mild steel bolts | 0.2 |
| Zinc plated steel bolts | 0.2 |
| Lubricated steel bolts | 0.18 |
| Cadmium plated steel bolts | 0.16 |
| With bowman anti-seize | 0.12 |
| With bowman-grip nuts | 0.09 |
It is estimated that roughly 90% of the input energy is lost in overcoming the mating friction under the head (collar) and between the thread or nut and its mating threads. Consequently only the remaining 10% of input energy is turned into bolt stretch.
This calculation is for a snap-fitting hook of rectangular cross section.There are two types which can be choosen for the calculation. Type 1 is a snap-fitting hook of a constant rectangular cross section and Type 2 is a snap-fitting hook of rectangular cross section with a constant decrease in thickness from h at the root to h/2 at the end of the hook. Young modulus and Yield strength of the material have to be choosen. The Deflection Force is the force required to bend the arm the value of the introduced deflection (y). Introducing the friction coefficient of the material and the angle of the arm according with the shape represented in picture, the mating force is calculated. This is the force required for introducing the snap-fitting hook. The calculus allows to ensure that the yield strength of the material won’t be exceeded as long as the safety coeficient is higher that 1. This calculation is an approximation because of we are only taking into account the shear due to bending.
The NPSH is related to the problem of cavitation. Cavitation means that the liquid pumped vaporizes within the pump which causes breakdown of suction column and head, loud noise, heavy vibration leading to erosion or pitting and possibly destruction of the impellers. The condition for operation without cavitation is:
NPSHa > NPSHr
Where:
NPSHa: NPSH available, of the plant.
NPSHr: NPSH required, of the pump. Lower value of NPSHr means greater the suction capability.
Usually is used a safety allowance of 0.5m.
P: Gas pressure. If the suction tank is open the gas pressure correspond to the atmospheric pressure (1 bar).
Vp: Vapour pressure of the fluid pumped at a given temperature.
ρ: Density of the fluid pumped.
g: gravitational constant 9.81 m/s2
S: Suction head. Vertical distance between suction tank and pump center line. (- ) for operation under suction lift conditions and (+) for operation under flooded suction conditions.
H: Head loss for the maximum flow in pipes, bends and valves on the suction side due to friction.
This calculator performs Pressure Drop Calculations for pipework. Additionaly, related parameters such as Reynolds, fluid velocity, average residence time, etcetera are presented. The Pressure Drop calculation takes into account other components as well. It requests the user for input about bends, elbows and other appendages/equipment components, which induce extra pressure loss. The program represents the total resistance in terms of equivalent pipe length values.
Determine if the thread is tapered or parallel/straight.
Measure the thread with a caliper at the beginning and the end. If the diameters increase for a male end or decrease for a female end, the thread is tapered. If it is the same value the thread is straight/parallel.
Determine the thread size and type. Imperial sizes are normally common fractions ¼”=0.25”.
Measure the outside diameter OD for male and inside ID for female threads.
If the thread is tapered measure the diameter of 4th or 5th full thread.
The diameter measurement obtained in this step may not be exactly the same as the listed nominal size for the given thread. This variation is due to manufacturing tolerances.
Determine the pitch for metric or the amount of threads per inch (T.P.I) for imperial sizes.
In both cases Thread pitch gauges can be used.
| TPI | 28 | 27 | 24 | 20 | 19 | 18 | 16 | 14 | 12 | 11.5 | 11 | 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thread pitch (mm) | 0.91 | 0.94 | 1.06 | 1.27 | 1.34 | 1.4 | 1.59 | 1.81 | 2.12 | 2.21 | 2.31 | 3.18 |
Check for any markings on fitting or equipment which may be a clue to thread type. Country of origin may provide a clue.
Europe (DIN,BSP), America (NPT, JIC, UNO, ORFS), UK/Australia (BSP), Japan (JIS).
| Symbol | Angle | Parallel/tapered | Standard | Description | Application |
|---|---|---|---|---|---|
| A/B | 60° | Parallel | DIN 4503, ISO 1222 | Tripod connection thread | Connections to photografic equipment. |
| ACME-C | 29° | ANSI B1.5 (1977) | Acme thread centralizing | ||
| ACME-G | 29° | ANSI B1.5 (1977) | Acme thread general purpose | ||
| AMO | 55° | ANSI B1.11 (1958) | American standard microscope objective thread | ||
| ANPT | 60° | MIL-P-7105 | Aeronautical national form taper pipe thread | ||
| API | 60° | American national taper form thread for petroleum installations | |||
| BA | 47°30' | BS93 (1951) | British association thread | ||
| BSC | 60° | BS811 (1950) | British norm thread for bicycles | ||
| BSF | 55° | Parallel | BS84 (1956) | Whithworth fine thread | |
| BSW | 55° | Parallel | BS84 (1956) | Whithworth coarse thread | |
| E | - | DIN 40400, DIN 49612, DIN 49610, DIN 49625 | Edison form thread | Electrical thread. | |
| EG M | 60° | Parallel | DIN 8140-2 | Metric ISO thread for helical coil wire screw thread inserts | For wire thread inserts. |
| EG-UNC | 60° | Parallel | MS 33537 | Unified coarse thread series for helical coil wire screw thread inserts | |
| EG-UNF | 60° | Parallel | ASME B18.29.1 | Unified fine thread for helical coil wire screw thread inserts | |
| FG | 60° | Parallel | DIN 79012 | Bicycle thread | For cycles and motor-scooters. |
| G | 55° | Parallel | DIN ISO 228, DIN 6630 | Pipe parallel ISO thread | For pressure tight joints are not made on the thread. External and internal pipe thread. Packaging; external thread for barrels. |
| G | 55° | Parallel | BS2779 (1973) | Pipe whitworth thread (BSP)parallel | |
| Gf | Tapered | DIN 4930 | Round tapered thread | Tubes and tunneling | |
| Gg | 60° | Tapered (1:16) | DIN 4941 | Tapered thread | For drill pipes in water and rock drilling, mining. |
| Gg | 30°-30° | Tapered (1:4) | DIN 20314 | Tapered thread | For drill pipes in water and rock drilling, mining. |
| GL | 30°-60° | Parallel | DIN 168-1 | Cylindrical round thread | For glass containers. |
| Glasg | 30°-50° | Parallel | DIN 40450 | Glasg thread for glass | Electric industry: glass fittings, protection glasses. |
| HA-HB | DIN 58810 | Bone screw thread | For surgical implants, external and internal thread. | ||
| KT | 20° | Parallel | DIN 6063 | Trapezoidal thread | Preferably for packages made of plastics. |
| LN | 60° | Parallel | LN 9163, EN 2158 | ISO Metric thread for aviation | Aviation and aerospace. |
| M | 60° | Parallel | DIN 13, DIN 14, ISO 68, DIN 6630, LN 9163, DIN 2510 | Metric coarse ISO thread | General engineering, watches, fine work, packaging; external thread for barrels, aviation, aerospace and bolted connections with reduced shank. |
| M | 60° | Tapered (1:16) | DIN 158 | Taper metric ISO thread | Plugs and grease nipples. |
| MF | 60° | Parallel | DIN 13, DIN EN 60423 | Metric fine ISO thread | |
| MFS | 60° | Parallel | DIN 8141-1 | ISO Metric thread for tight fit | |
| MJ | 60° | Parallel | DIN ISO 5855 | Metric ISO thread for aeronautics | Aviation and aerospace. |
| N | 60° | ANSI B1.1 (1960) | American national 8-12-16 TPI pitch series (8N, 12N, 16N) | ||
| N-BUTT | 45°+5° | ANSI B1.9 (1973) | American BUTTRESS thread | ||
| NC | 60° | ANSI B1.1 (1960) | American national coarse thread series | ||
| NEF | 60° | ANSI B1.1 (1960) | American national extra fine thread series | ||
| NF | 60° | ANSI B1.1 (1960) | American national fine thread series | ||
| NGO | 60° | ANSI/ASME-B1.20.1 (1983) | National gas outlet thread (specify RH or LH) | ||
| NGS | 60° | ANSI/ASME-B1.20.1 (1983) | National gas straight thread | ||
| NGT | 60° | ANSI B57.1 (1977) | National gas taper thread (see also SGT) | ||
| NH | 60° | ANSI B2.4 H28 (1966) | American national firehouse and hose coupling thread | ||
| NPS | 60° | American standard straight pipe thread NSPC & NPSM | |||
| NPSC | 60° | ANSI/ASME-B1.20.1 (1983) | American standard straight pipe thread in pipe couplings (marked NPS) | ||
| NPSF | 60° | ANSI B1.20.3 (1976) | Dryseal American standard internal straight pipe thread (fuel) | ||
| NPSH | 60° | ANSI/ASME-B1.20.1 (1983) | American standard straight pipe thread for hose couplings | ||
| NPSI | 60° | ANSI B1.20.3 (1976) | American standard intermediate internal straight pipe thread | ||
| NPSL | 60° | ANSI/ASME-B1.20.1 (1983) | American standard straight pipe thread for loose-fitting mechanical joints | ||
| NPSM | 60° | ANSI/ASME-B1.20.1 (1983) | American standard straight pipe thread for free-fitting mechanical joints | ||
| NPT | 60° | Tapered (1:16) | ANSI/ASME-B1.20.1 (1983) | American standard tapered pipe thread | For threads with dryseal material. |
| NPTF | 60° | Tapered (1:16) | ANSI B1.20.3 (1976) | American standard tapered pipe thread (fuel) | For threads without dryseal material. |
| NPTR | 60° | ANSI/ASME-B1.20.1 (1983) | American standard taper pipe thread for railing joints (tap market NPT) | ||
| NS | 60° | ANSI B1.1 (1960) | American national thread special pitches | ||
| Pg | 80° | Parallel | DIN 40430 | Steel electrical conduit thread | For electric installations. |
| PTF | 60° | ANSI B1.20.1 (1976) | Dryseal SAE short taper pipe thread | ||
| R | 55° | Parallel | DIN 259 | Pipe parallel whitworth thread | For pressure tight joints are not made on the thread. Piping, do not use in new designs. |
| R | 55° | Tapered (1:16) | BS21 (1985), DIN EN 10226-1, ISO 7-1, DIN 2999, DIN 3858 | External dryseal pipe taper thread (BSPT) | Tapered Whitworth pipe thread where pressure-tight joints are made on the threads. |
| Rc | 55° | Tapered (1:16) | BS21 (1985), DIN EN 10226-1, ISO 7-1 | Internal dryseal pipe taper thread (BSPT) | Tapered Whitworth pipe thread where pressure-tight joints are made on the threads. |
| Rd | 30° | Parallel | DIN 405, DIN 20400, DIN 15403, DIN 7273 | Rounded thread | General, for mining industry, for lifting hooks, for steel sheet items and related joints. |
| RMS | 55° | Parallel | DIN 58888 | RMS-thread | Objective for microscope. |
| Rp | 55° | Parallel | DIN 2999, DIN 3858 | Internal dryseal parallel thread | Internal thread for pipes and fittings. |
| Rp | 55° | Parallel | BS21 (1973), DIN EN 10226-1, ISO 7-1 | Pipe parallel thread (BSPP) | Cylindrical Whitworth pipe thread where pressure-tight joints are made on the threads. |
| S | 30°+3° | Parallel | DIN 513, DIN 20401 | Saw form thread | General. Mining industry. |
| S | 45° | Parallel | DIN 2781 | Saw form thread | For machine tools, hydraulic presses. |
| S | 105° | Tapered (7°30') | DIN 71412 | Self forming taper external thread | Taper lubricating nipple. Similar to DIN 158 but 105° thread angle. |
| SB | Manufacturers stovebolt standards thread | ||||
| SGT | 60° | ANSI B57.1 (1977) | Special gas taper thread | ||
| SPL-PTF | 60° | ANSI B1.20.3 (1976) | Dryseal special taper pipe thread | ||
| ST | 60° | Parallel | DIN 7970, DIN EN ISO 1478 | Sheet metal screw thread | For tapping screws. |
| STI | 60° | Special thread for helical coil wire screw thread inserts | |||
| STUB-ACME | 29° | ANSI B1.8 (1977) | Stub Acme thread | ||
| Tr | 30° | Parallel | DIN 103, DIN 380, DIN 263, DIN 6341, DIN 30295 | Trapezoidal thread | General, for rail vehicles, for collet chucks. |
| UN | 60° | ANSI B1.1 (1982) | Unified 8-12-16 TPI pitch series | ||
| UN-8 | 60° | ASME B1.1 | Unified thread for special diameters and pitches | ||
| UNC | 60° | ANSI B1.1 (1982) | Unified coarse thread series | ||
| UNEF | 60° | ANSI B1.1 (1982) | Unified extra fine thread series | ||
| UNF | 60° | ANSI B1.1 (1982) | Unified fine thread series | ||
| UNJ | 60° | BS 4048 (1978) | Unified constant pitch with a 0,15011P to 0,18042P controlled root radius | ||
| UNJC | 60° | BS 4048 (1978), ASME B1.15 | Unified coarse thread with a 0,15011P to 0,18042P controlled root radius | ||
| UNJEF | 60° | BS 4048 (1978) | Unified extra fine thread with a 0,15011P to 0,18042P controlled root radius | ||
| UNJF | 60° | BS 4048 (1978), ASME B1.15 | Unified fine thread with a 0,15011P to 0,18042P controlled root radius | ||
| UNM | 60° | ASA B1.10 (1958) | Unified miniature thread series | ||
| UNS | 60° | ANSI B1.1 (1982) | Unified thread special pitches | ||
| V | 60° | 60° "V" thread with truncated crest and root(flatted to the user's specifications) | |||
| Vg | 60° | Parallel | DIN 7756 | Valves thread | Valves for tires. |
| W | 55° | Parallel | DIN 477 | Parallel whitworth thread | Cylindrical thread for side connections. |
| W keg | 55° | Tapered (3:25) | DIN 477, DIN EN 144-1, DIN EN 629-1, DIN EN ISO 11116-1 | Tapered thread for screw sockets | Gas cylinders, thread for side nozzles. |
This calculator is valid for simple and double effect. For simple effect the value provide by the calculator has to be divided by 2.
Leakage is not taken into the calculator.
