We Ship Worldwide! Shipping information.
OWNER'S MANUAL

Technical data, pressure-to-force table, part numbers by end fitting, installation, maintenance and troubleshooting for the Selden HT-W8/10 and HT-W12/14 hydraulic backstay tensioners (for an external pump system).

DocumentSelden Hydraulic Backstay Tensioner HT Owner's Manual
FormatPDF · 8 pages · 0.3 MB
LanguageEnglish
Download PDFBuy
SpecificationsPart NumbersInstallationMaintenanceTroubleshootingProducts
Selden Hydraulic Backstay Tensioner HT — Owner's Manual

Technical Data

The HT is a cylinder only: it connects to a hydraulic system with a pump, a release valve and a holding tank. Pumping oil in contracts it and pulls on the backstay; releasing the pressure lets the backstay extend it as oil returns to the tank.

HT-W8/10 HT-W12/14
Safe working load (kN) 44 85
Cylinder outer diameter (mm) 62 80
Weight (kg) 5,5 12
Hole upper / lower (mm) ø12.5 ø16.5
Pin upper / lower (mm) Ø12 ø16
Fork width X upper / lower 14 / 21 16 / 16
Fork depth Z upper / lower 30 / 22 34 / 32
Maximum working pressure 345 bar 345 bar

Oil: ISO VG 46, DIN 51524 part 3, HVLP 46; recommended Statoil Hydraway HVXA 46; comparable Castrol Hyspin AWH-M 46, Shell Tellus S2 V 46.

Pressure (bar) HT-W8/10 force (kN) HT-W12/14 force (kN)
25 3.2 6
50 6.4 12.3
75 9.6 18.5
100 12.7 24.6
125 15.9 31
150 19.1 37
175 22.3 43
200 25.5 48
225 28.7 55
250 31.9 60
275 35 68
300 38.3 74
325 41.4 80
345 44.0 85

Versions & Part Numbers

HT-W8/10

Part No. End type Anodize colour Thread UNF Ø pin (mm) Length min–max (mm)
580-003-10 Stud Nature 5/8"-LH 16 L1=826-1246 Ask us to source it →
580-004-10 Stud Black 5/8"-LH 16 L1=826-1246 Ask us to source it →
580-003-11 R-screw body Nature 5/8"-RH 16 L2=836-1404 Ask us to source it →
580-004-11 R-screw body Black 5/8"-RH 16 L2=836-1404 Ask us to source it →
580-003-21 Fork Nature – 16/16 L3=856-1276 Ask us to source it →
580-004-21 Fork Black – 16/16 L3=856-1276 Ask us to source it →

HT-W12/14

Part No. End type Anodize colour Thread UNF Ø pin (mm) Length min–max (mm)
580-007-10 Stud Nature 7/8"-LH 22 L1=912-1392 View part →
580-008-10 Stud Black 7/8"-LH 22 L1=912-1392 View part →
580-007-11 R-screw body Nature 7/8"-RH 22 L2=936-1566 Ask us to source it →
580-008-11 R-screw body Black 7/8"-RH 22 L2=936-1566 Ask us to source it →
580-007-21 Fork Nature – 22/22 L3=957-1437 Ask us to source it →
580-008-21 Fork Black – 22/22 L3=957-1437 Ask us to source it →

Related components / spare parts

Part No. Description
174-326-99 Rigging screw body, HT-W8/10 (SWL=44kN) View part →
174-328-99 Rigging screw body, HT-W12/14 (SWL=85kN) View part →
581-400-01 Fork, HT-W8/10, nature Ask us to source it →
581-401-01 Fork, HT-W8/10, black Ask us to source it →
581-402-01 Fork, HT-W12/14, nature Ask us to source it →
581-403-01 Fork, HT-W12/14, black Ask us to source it →

Installation

  • Have the hydraulic system professionally installed, using only hoses and connectors suitable for the marine environment and 345 bar working pressure. Keep impurities out of the system.
  • Hydraulic connection: 1/8" BSPP thread with flat surface for a seal washer; pressure-line connector 1/8" BSPP male with 60° cone.
  • Hoses, pump station and tank: see the Selden hand-operated pump station manual (597-145-E). Split pins: Selden "Hints and advice" (595-540-E) p.18.
  • To extend the rod during installation, attach a halyard to the rod end and open the pressure release valve on the pump station.

Maintenance & Storage

  • Rinse with fresh water regularly; rinse off all detergent (most corrode aluminium). Silicone-free wax protects the surfaces.
  • Service at intervals of no more than five years in normal use; more often for charter or circumnavigation. Inspect the hydraulic hoses at every service and replace any showing wear.
  • Storage: keep stainless wire and rigging off the aluminium (galvanic corrosion); store dry with air circulating, never wrapped in plastic.

Troubleshooting

Problem Cause / action
Rod movement is uneven Air in the hydraulic system (air compresses like a spring). Check the system for trapped air.
Tension decreases quickly in the backstay Oil leaking past the piston seals from the pressurized side. Check for external leaks such as past the rod seals; try the tensioner at its end positions. The cylinder needs service – contact Selden.
Tension not increasing when pumping Check the pump station makes pressure. If it does, disconnect the cylinder from the backstay and check it contracts fully under pressure; stopping short means oil has leaked past the piston seal. The cylinder needs service – contact Selden.

Hydraulic pressure can be dangerous: this work should be done by trained personnel.

Need a part that isn't listed? Ask us to source it and quote the part number from the PDF.

Products in this Manual