LC Pipe Combine

LC Pipe Combine is a three-socket node that does one thing: it takes a pipe and edits it with a second pipe. Whatever the edit pipe carries overwrites the top pipe's matching slots; everything else rides along untouched. Output is a single LC_PIPE.

That's it. No settings, no mode switch. Which is exactly why it's useful - it's the "patch this one value" tool for a bundle that's otherwise painful to touch.

Why bother

An LC_PIPE in this pack holds twenty-five slots: two sets of model/clip/VAE, image, mask, width, height, latent, batch, positive and negative prompts and conditioning, seed, total_steps, cfg_1, denoise, step_swap, cfg_2, sampler name, scheduler, detailer steps. If your graph has one loader feeding two branches, combining lets the second branch differ in one or two values without duplicating the whole loader-and-encoder setup.

The mechanism is the interesting part: empty slots in the edit pipe are ignored. Slots that were never set don't overwrite anything, so a deliberately skimpy pipe - built by LC Pipe (in/edit) with only two sockets wired - acts as a partial patch. Fill in steps and latent, leave the other twenty-three alone, and everything else passes through from the base pipe. Same idea as the pack's Aspect Ratio Pipe (In/Edit), where only the sockets you actually wire overwrite.

Wire the output into LC Pipe Out (or LC Sampler Configure Pipe Out) and keep going.

What it can't do

It replaces values; it can't clear them. There's no "set this slot back to nothing", because "empty" already means "leave it alone". If you need a slot gone, that's a different pipe.

It also isn't in-place. Combining produces a new pipe object; nodes downstream of the original pipe still see the original. If half your graph picked up your edit and half didn't, you're looking at two pipes and one of them is the old one.

And the standard warning for every context-bus node applies: the thing that makes a pipe legible also hides what's inside it. With a combine node you've now got two sources feeding one bundle, and the failure - unpacking a model that predates your LoRA - becomes that much easier to make. Keep combines near where their output is consumed, not shoved into a corner of the graph.

Install

cd ComfyUI/custom_nodes
git clone https://github.com/lonecatone23/ComfyUI_LC123_nodes.git

Or find it in ComfyUI Manager as ComfyUI LC123 Nodes. Zero dependencies - the pack has no requirements.txt and only uses what ComfyUI already ships. Restart after cloning; the console prints an [LC123] + line per module as it loads.

If the LC_PIPE sockets show as unconnected types on load, ComfyUI hasn't fully reloaded the pack - restart, then Ctrl+F5 in the browser after any update. Pipes from older workflow versions can arrive with slots empty, and because empty means "pass through", that shows up as a missing value rather than an error.