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Selecting the right LCN closer requires three decisions: size (1 through 6 based on door width, weight, and ADA requirements), mounting type (regular arm pull-side, parallel arm push-side, or top jamb), and series (4040XP for high-traffic and exterior; 4030 or 1000 Series for moderate interior; 2010/5010 concealed for aesthetic applications; 4040SE Sentronic for fire and smoke barrier hold-open). Interior non-fire doors on accessible routes must not exceed 5 lbs opening force (ADA Section 404.2.9). Fire doors are exempt from the 5 lbf limit. Hydraulic valves adjust in this order: S (sweep speed) first, then L (latch speed), then B (backcheck). Parallel arm mounting requires one size higher than regular arm to compensate for reduced mechanical efficiency.
Door closers generate more misspecified orders, more callbacks, and more ADA complaints than almost any other commercial door hardware component. The core reason is that three separate decisions interact: the spring size, the arm mounting type, and the series. Getting one of these wrong produces a door that either slams shut too fast, fails to latch consistently, exceeds the ADA opening force limit, or requires a complete arm change to correct. Getting all three right means the door functions correctly for years without adjustment.
Browse the complete LCN door closer parts catalog at SecurityParts.com, including parts for the LCN 4040XP, 4000 Series, 1000 Series, and concealed closer series. For pre-order selection support, call 845-935-0301 or use the contact page.
How to Choose the Right Closer Size: What Sizes 1 Through 6 Actually Mean
ANSI/BHMA A156.4 defines six closer sizes based on the spring force needed to reliably close and latch a specific door. The size number is not a product generation or a quality tier. It describes the spring tension: higher numbers mean more closing force, which is needed for wider, heavier, or more exposed doors.
| Size | Interior Door Width | Exterior Door Width | Typical Application | ADA Note |
|---|---|---|---|---|
| 1 | Up to 2'6" | Not recommended | Small interior utility, closet | Typically meets 5 lbf |
| 2 | Up to 2'9" | Not recommended | Light interior corridor, residential | Typically meets 5 lbf |
| 3 | Up to 3'0" | Up to 2'6" | Standard commercial interior (most common) | Verify with gauge |
| 4 | Up to 3'6" | Up to 3'0" | Heavy commercial interior, light exterior | May exceed 5 lbf; verify |
| 5 | Up to 4'0" | Up to 3'6" | Exterior entry, wind-exposed, high traffic | Exterior only; not ADA interior |
| 6 | Up to 5'0" | Up to 4'0" | Heavy exterior, institutional, vestibule | Exterior only; not ADA interior |
The LCN 4040XP ships pre-adjusted to size 3 and is field-adjustable from size 1 through 6 using the green dial indicator on the closer body. This adjustability means a single closer body can serve most standard door widths, but it does not eliminate the need to verify actual opening force after adjustment. The dial position is a starting point, not a guarantee of code compliance.
ADA Door Closer Requirements: Opening Force and Sweep Timing
ADA Standards Section 404.2.9 sets two requirements for door closers on accessible routes.
The 5 lbf Opening Force Rule
Interior hinged, sliding, or folding doors that are not fire-rated must require no more than 5 pounds-force to open when measured at the door handle or push face. This force is measured perpendicular to the door from a fully closed and latched position. The measurement point matters: measuring from the hinge edge produces a lower force reading than the handle edge, but the ADA measurement is at the door face closest to the latch side. Peak force is what counts, not average force.
Exterior doors are not subject to the federal 5 lbf cap, but most state codes and ANSI A117.1 set a limit of 8.5 lbf for exterior accessible entrances. Check your state's specific code before assuming exterior doors have no opening force limit.
Fire Door Exception
Fire-rated doors are explicitly exempt from the 5 lbf opening force limit because fire doors must close and latch against their door seals with enough force to maintain the fire and smoke separation under elevated temperature conditions that cause door frame expansion. A fire door closer adjusted to 5 lbf may fail to latch against a swollen frame during a fire event. This is why fire stairwell doors and fire corridor doors feel harder to push open than standard commercial doors. That is not a defect and not a code violation. It is the required performance level for fire-rated assemblies.
The 5-Second Sweep Timing Requirement
ADA also requires that a door closer allow the door to travel from a 90-degree open position to within 12 degrees of the latch in at least 5 seconds. This minimum time allows a person using a wheelchair, walker, or crutches to clear the door opening before the door closes on them. The S valve (sweep speed valve) controls this motion. Setting the S valve too fast (closing the door quickly) violates this requirement even if the opening force is within limits. Both requirements must be met simultaneously.
Arm Mounting Types: Regular, Parallel, and Top Jamb
Regular Arm (Hinge Side Mount)
Regular arm mounting places the closer body on the pull side of the door at the hinge side of the door face. The arm connects the closer body to the door frame at the header. This is the default, most mechanically efficient mounting position. The arm alignment is optimized so the full spring force is applied to the door through a direct mechanical path. Regular arm is the correct first choice for any door where it is physically possible.
The LCN 4010 is specifically designed for regular arm pull-side mounting and uses a mounting hole pattern of 2-1/2 inches vertical by 6 inches horizontal (center to center). The 4040XP uses a staggered pattern of 2-1/4 inches vertical by 5 inches horizontal. These patterns are not interchangeable: a 4010 arm will not bolt to a 4040XP body or vice versa.
Parallel Arm (Push Side Mount)
Parallel arm mounting places the closer body on the push side of the door with the arm running parallel to the door frame when the door is closed. The closer mounts at the top rail of the door, and the shoe (the bracket at the end of the arm) mounts to the door frame head. The arm swings out as the door opens, positioning parallel to the frame at full close.
Parallel arm is used when the closer must be on the push side (where the hinge side of the door is inaccessible or when the specification requires the closer not to be visible from the pull side corridor). It is also the preferred mounting for wide vestibule doors where the arm geometry works more cleanly in parallel configuration. The mechanical efficiency reduction in parallel arm requires one size larger spring than regular arm for the same door.
The LCN 4110 series is dedicated to parallel arm push-side mounting. The 4040XP includes a parallel arm shoe (4040XP-62PA) as part of its tri-pack to accommodate parallel arm mounting on the universal body.
Top Jamb (Frame Head Mount)
Top jamb mounting places the closer body on the door frame head (the top of the frame) rather than the door itself. The arm extends from the closer body down to the door face. This mounting is required on glass storefront applications where the door top rail is too narrow to mount a closer body, and on narrow-profile aluminum frame doors where the door rail depth does not accommodate a surface closer.
Top jamb has more geometric limitations than the other mounting types: the frame head reveal depth, the ceiling height above the frame, and the door swing angle all affect arm selection and mounting plate requirements. The LCN 4020 series is specifically designed for top jamb push-side mounting. The 4040XP requires the 4040XP-18TJ plate for top jamb mounting when the head frame reveal is less than 3-1/2 inches.
LCN Closer Series Comparison: Which Series for Which Door
LCN 4040XP
The industry benchmark for high-traffic, exterior, institutional, and abuse-prone openings. Cast iron cylinder, forged steel arm, double heat-treated pinion, full complement low-friction bearings. Non-PRV (pressure relief valve) design. Size 1 to 6 adjustable via green dial. Tri-pack covers regular, parallel arm, and top jamb from one unit. Interior doors to 5 feet wide, exterior to 4 feet wide. 30-year warranty.
LCN 4010 / 4020 / 4110
Dedicated-mount versions of the 4000 Series using the same heavy-duty body as the 4040XP but packaged for a single mounting position. 4010: regular arm pull side. 4020: top jamb push side. 4110: parallel arm push side. Different mounting hole patterns from the 4040XP. Specified when only one mounting type is needed and the project does not require tri-pack versatility.
LCN 4030
A mid-range universal closer for moderate traffic interior and exterior applications. Covers regular arm, parallel arm, and top jamb from one unit. Fully adjustable closing speeds and backcheck. Compact and cost-effective versus the 4040XP for office suites, moderate corridors, and standard commercial interior openings where full institutional-grade construction is not required.
LCN 1000 Series
Slim profile closer for interior doors in lower-traffic environments including offices, classrooms, and hotel corridors. Same arm control options as the 4000 Series. Ships without cover as standard (optional plastic or metal covers available). Same finish options as 4000 Series. Specified when the door is interior, moderate traffic, and full 4040XP institutional grade is not required. Significant cost advantage on large interior-only projects.
LCN 4040SE Sentronic
4040XP body with an integrated electromagnetic hold-open coil that connects to the building fire alarm system. Holds fire and smoke barrier corridor doors open during normal building operations and releases them automatically when the fire alarm panel activates, allowing the door to close under spring force. Required on fire-rated and smoke barrier doors where hold-open function is needed without a separate wall-mounted electromagnetic holder.
LCN 2010/5010 Concealed
Concealed overhead closers with the cylinder housed in the door frame head and the arm and track concealed in the door top rail. Provides a completely clean appearance with no visible hardware on either door face. Specified in lobbies, courtrooms, executive corridors, and high-end retail where visible surface closers are architecturally unacceptable. Higher installation cost and requires correct frame and door top rail dimensions. Parts covered in the SecurityParts.com LCN concealed closer catalog.
The Non-PRV Design: Why It Matters on the 4040XP
PRV stands for pressure relief valve, a safety valve found in some door closer hydraulic systems that releases pressure if the hydraulic circuit is overloaded. On closers with PRV design, an impact event (a door being kicked open or slammed by wind) can trigger the PRV, releasing hydraulic fluid and causing the closer to lose its adjustment. The closer then requires re-adjustment and can potentially develop a permanent hydraulic leak through the relief valve pathway.
The LCN 4040XP uses a non-PRV design. The hydraulic circuit is sealed without a pressure relief pathway, and the closer body is built with sufficient structural strength to absorb impact forces without requiring a pressure relief mechanism. The result is a closer that maintains its adjustment setting after abuse events and does not develop PRV-related hydraulic fluid loss. This is one of the most significant durability differences between the 4040XP and lower-cost commercial closers that use PRV design to reduce manufacturing costs.
How to Adjust LCN Door Closer Hydraulic Valves
LCN surface closers have three hydraulic adjustment valves, and the order of adjustment matters because each valve's setting affects the motion the next valve must control. Adjusting out of sequence wastes time and produces settings that interact with each other in ways that are difficult to diagnose.
S Valve: Sweep Speed First
The S valve controls the main door travel from fully open (90 degrees) to approximately 10 to 15 degrees before the latch position. Set this so the door closes in 5 to 7 seconds from 90 degrees for interior doors, and 4 to 6 seconds for exterior doors. Clockwise rotation slows the sweep. Counterclockwise speeds it up. The ADA minimum of 5 seconds applies from 90 degrees to 12 degrees from the latch on accessible routes. Set S first because latch speed and backcheck both interact with the position at which sweep ends.
L Valve: Latch Speed Second
The L valve controls the door movement from the point where sweep ends (approximately 15 degrees from latch) to the fully closed and latched position. This is the last phase of closing. Too fast produces an audible slam that annoys occupants and stresses the latch mechanism. Too slow causes the door to drift toward closed without positive latching, particularly against weatherstripping resistance. Adjust for a smooth, firm close that audibly latches without slamming. Clockwise slows latch speed.
B Valve: Backcheck Third
Backcheck controls the resistance the closer applies when the door is pushed past approximately 70 to 75 degrees of opening. It prevents the door from slamming fully open against a wall stop, which damages the door, frame, and closer arm. Clockwise increases backcheck resistance. Engage backcheck on all exterior doors exposed to wind and on any door where someone could push it hard enough to hit the wall. Interior low-traffic doors may not need backcheck engaged. Set B last because backcheck position only matters after sweep and latch speeds are established.
Fire Door Closer Requirements
Closers on fire-rated door assemblies have requirements beyond standard commercial applications. Every fire door must return to a fully closed and latched position automatically after each use, without exception. This requirement eliminates all free-swing and permanent hold-open configurations on fire-rated openings unless the hold-open device is an electromagnetic unit connected to the fire alarm system that releases on alarm.
Spring Size on Fire Doors
Fire doors require sufficient spring force to close against their seals under conditions where the door frame may have expanded slightly from heat exposure. A fire closer set to minimum spring size to meet ADA may produce a door that closes perfectly under normal conditions but fails to latch against an expanded frame during a fire event. Fire door closers should be set to a spring size that provides positive latching against the full compression of the door seals, even if this exceeds the 5 lbf ADA limit. The ADA fire door exemption exists precisely for this reason.
LCN 4040SE Sentronic for Hold-Open
When fire door corridor doors must be held open during normal building operations (for air circulation, visual supervision, or traffic flow) but must close on alarm, the LCN 4040SE Sentronic integrates the closer and electromagnetic hold-open in a single unit. The electromagnetic coil holds the door open during normal operation. When the fire alarm panel activates, current interruption to the coil releases the door and the spring drives it to closed and latched position. No separate wall-mounted electromagnet is required. The Sentronic is the correct specification for fire door hold-open applications and is available with the full 4040XP heavy-duty closer body.
Browse the complete LCN door closer parts catalog at SecurityParts.com. For specific series part numbers and diagrams, browse the LCN parts catalog by series. For related commercial door hardware, browse Von Duprin exit device parts, Schlage L Series mortise lock parts, and the complete all products and parts catalog.
Why Choose SecurityParts.com for LCN Door Closer Parts
Non-PRV design explanation, seasonal re-adjustment warning, parallel arm size correction, winter compliance failure, and same-day shipping on stocked LCN parts.
Non-PRV Design Detail
We document the 4040XP non-PRV design and explain how to distinguish PRV bleed leaks from seal failures. No other parts supplier documents this at the product ordering stage.
Seasonal Compliance Warning
We document that closers adjusted to ADA compliance in summer frequently violate the 5 lbf limit in winter due to hydraulic fluid thickening. Winter-only ADA complaints are almost always a seasonal re-adjustment issue, not a failed closer.
Parallel Arm Size Correction
We document the one-size increase required for parallel arm mounting. Installers who skip this step produce doors that fail to latch in wind on exterior openings or exceed ADA limits on interior accessible routes.
Same-Day Shipping
LCN 4040XP, 4000 Series, 1000 Series, and concealed closer parts ship same day from US warehouses. Call 845-935-0301 or use the contact page for series and size confirmation.
What Makes SecurityParts.com Different for LCN Door Closer Parts
- We document the seasonal hydraulic fluid thickening issue that produces winter ADA compliance failures on closers correctly adjusted in summer. This is the most common cause of winter ADA door complaints in commercial buildings and is documented nowhere in standard specification content.
- We document the non-PRV design of the 4040XP and explain how to diagnose PRV bleed leaks versus seal failures. This diagnostic detail prevents unnecessary cylinder replacements when the real issue is a specific seal failure.
- We document the parallel arm size increase requirement and explain why parallel arm mounting reduces mechanical efficiency. Installers who miss this produce either latching failures or ADA violations depending on which direction they err.
- We document the fire door spring size conflict with ADA: fire doors are exempt from the 5 lbf limit and should be set above this threshold for reliable latching against expanded frames during fire conditions.
- We carry all LCN door closer replacement parts across the complete LCN parts catalog alongside Von Duprin exit device parts, electric strike parts, and cylindrical lock parts for full commercial door hardware service in one order.
- Free shipping on orders over $450. Same-day shipping from US warehouses on stocked parts. 30-plus years of commercial door hardware experience.
Related Parts and Products at Security Parts
LCN door closers appear on every commercial door alongside locks, exit devices, and access control hardware. Most service calls cover multiple components simultaneously.
For Von Duprin exit device parts on fire-rated corridor doors in the same building as LCN closers, browse the exit devices catalog. For Von Duprin electric strike parts on access-controlled openings that also carry LCN closers, browse the electric strikes catalog. For Schlage L Series mortise lock parts on main entries with LCN 4040XP or Sentronic closers, browse the mortise locks catalog. For ND Series cylindrical lock parts on corridor doors with LCN 4000 or 1000 Series closers, browse the cylindrical locks catalog.
Browse the complete all products and parts catalog to source Schlage, Falcon, Von Duprin, LCN, and Detex hardware across the complete facility in a single session.
Frequently Asked Questions About LCN Commercial Door Closer Selection
What do the door closer size numbers 1 through 6 mean and how do I choose the right one?
Sizes 1 through 6 describe spring force: size 1 is lightest for small interior doors, size 6 is heaviest for wide exterior doors in high wind. Standard interior commercial doors (3 feet wide) typically need size 3 or 4. Exterior doors start at size 4 or 5. When using parallel arm mounting, increase by one size. The LCN 4040XP ships at size 3 and is field-adjustable via green dial. Always verify opening force with a calibrated gauge after adjustment to confirm ADA compliance.
What is the ADA opening force limit for door closers and which fire door exception applies?
ADA Section 404.2.9: interior non-fire-rated hinged doors must open with no more than 5 pounds-force. ADA also requires at least 5 seconds for door travel from 90 degrees to 12 degrees from the latch. Exterior doors are not subject to the federal 5 lbf limit but most states cap them at 8.5 lbf under ANSI A117.1. Fire-rated doors are explicitly exempt from the 5 lbf limit because fire doors need sufficient spring force to latch against seals under elevated temperature conditions.
What is the difference between regular arm, parallel arm, and top jamb door closer mounting?
Regular arm mounts the closer on the pull side at the hinge side of the door. Most mechanically efficient. Parallel arm mounts on the push side with the arm parallel to the frame when closed. Requires one size larger spring to compensate for reduced efficiency. Top jamb mounts the closer body on the frame head with the arm extending to the door face. Used on glass storefronts and narrow-rail aluminum doors where door-mounted closers will not fit.
What is the difference between the LCN 4040XP and the LCN 4010, 4020, and 4110 series?
The 4040XP is a universal tri-pack covering regular arm, top jamb, and parallel arm from one body, with a staggered hole pattern (2-1/4 inch by 5 inch center to center). The 4010 is regular arm pull-side only with a 2-1/2 inch by 6 inch hole pattern. The 4020 is top jamb push-side, same body as 4010. The 4110 is parallel arm push-side. Specify the 4040XP when a single universal body is needed across a project; specify the 4010/4020/4110 for dedicated single-mount installations where the different hole pattern is acceptable.
What is the correct order to adjust the hydraulic valves on an LCN door closer?
Always adjust S (sweep speed) first, then L (latch speed), then B (backcheck). Set S so the door closes from 90 degrees to near-latch in 5 to 7 seconds interior (5 seconds minimum for ADA). Then set L for smooth firm latching without slamming. Then set B for door opening resistance past 70 to 75 degrees. Cycle the door two to three times after each adjustment because hydraulic response lags before stabilizing. Re-check and re-adjust in winter as hydraulic fluid thickens in cold temperatures.
When should an LCN 1000 Series closer be specified instead of the 4040XP?
The LCN 1000 Series is appropriate for interior, moderate-traffic doors in offices, classrooms, and hotel corridors where the full institutional-grade construction of the 4040XP is not required. It ships without a cover as standard and has a slimmer profile. The 4040XP is the correct specification for high-traffic, exterior, institutional, abuse-prone, and fire-rated applications. On large interior-only projects, specifying 1000 Series for interior doors and 4040XP for perimeter and high-use openings is the cost-effective approach.